hacking

	==Phrack Classic==

	Volume Three, Issue 32, File #6 of 12

	+----------------------------------+
	] Exploration of: ]
	] Automatic Teller Machine Cards ]
	] ]
	+----+-------------------------+---+
	] Written by: ]
	] Jester Sluggo ]
	] ]
	] Released: May 13, 1989 ]
	](to Black-Ice:For Review)]
	] Released: Jan 12, 1990 ]
	] (to Phrack Inc.) ]
	] Released: Nov, 10, 1990 ]
	] (to Phrack Classic) ]
	+-------------------------+


	With the North American continent the being the worlds biggest
	consumer of goods and services liquidity of the banking system has
	become an important factor in our everyday lives. Savings accounts
	were used by people to keep money safe and used by the banks to
	provide money for loans. However, due to 'Bankers Hours' (10 AM to
	3 PM) it was often difficult for people to get access to thier
	money when they needed it.

	The banking system then created the Checking Account system. This
	system allowed people to have much easier access to thier money.
	Unfortunately the biggest drawback of this system is that people can
	not manage thier own money and accounting procedures. Millions of
	times each day throughout the North American continent people are
	writing checks for more money than they have in thier savings accounts.
	This drawback also causes the already-backed up judicial system to
	become backed up further. The banking system soon reacted to this
	problem by producing 'check verification' methods to prevent people
	from forgery, and overdrawing from thier accounts.

	"Money makes the world go 'round" and there are many different ways
	to make this world spin. Today we have checking accounts, credit
	cards, travelers checks, and the most 'liquid' form of money: cash.
	Cash transactions are untrackable and widely accepted, so I feel
	the "Paperless Society" will never happen. Automated Teller Machines
	provide consumers with 24-hour access to cash-sources. By simply
	inserting a plastic card into the machine and keypadding-in the
	owners' "account password", you can access the owners bank account
	and receive cash in-hand. This file will explain some details of
	the automated tellers and the plastic card used by the Teller-system.

	The automated teller is connected by wires and cables to a "Main
	Computer". During each transaction the teller sends signals to
	the main computer. The main computer records each transaction
	(a deposit or withdrawl) and updates the card-holders account.
	It also sends 'approval' or 'denial' signals to the ATM in regard
	to the transaction requested. If a card-holder attempts to withdraw
	$150.00 from his account and he has only $100.00 in it, the main
	computer will tell the ATM to deny the transaction.

	The ATM has 2 compartments to store cash in. The first is the "deposits"
	compartment. This is a small area that receives the daily deposits.
	It is located in the upper-part of the machine, near all the mechanical
	devices. However, because most ATM transactions are withdrawls the
	complete bottom-half is filled with cash where the withdrawls are
	extracted from.

	The plastic card inserted into the machine is the same size as a
	credit card. The front of the card is embossed with information
	about the card-holder. The back-side of the card has a thin strip
	of magnetic tape which also holds some important information.

	+--------------------------+ +--------------------------+
	] CIRRUS ] ]--------------------------]
	] INSTANT CASH CARD ] ]/////(magnetic strip)/////]
	] ] ]--------------------------]
	] Acct: 12345675 Exp. ] ] ]
	] Joe Schmoe 01/91 ] ] "card-holders signature" ]
	] ] ] ]
	+--------------------------+ +--------------------------+
	Front-side Back-side

	When a cardholder inserts his card into the machine and requests a
	transaction, the machine reads the embossed information from the
	front-side and compares it with the data stored on the magnetic
	strip; looking for a 'match' of the information on both sides.

	The information on the front-side is easily readable with your
	eyes. However, you can not read the data on the magnetic-strip
	so easily. You may ask , "What is stored on the magnetic strip ?".
	The answer is; the same information as the embossing plus some
	'confidential' information regarding the cardholders' financial
	status is stored there. The magnetic strip has 3 "tracks" on it.
	The first track can store 210 BPI (Bytes per inch), and the second
	stores 75 BPI, and the third stores 210 BPI. So, we have:

	+---------------------------+
	Track 1: (210 BPI density)
	+---------------------------+
	Track 2: ( 75 BPI density)
	+---------------------------+
	Track 3: (210 BPI density)
	+---------------------------+

	THE MAGNETIC STRIP


	Now, here's the information stored on each track of the strip in
	my example:

	Track 1: " ;B 12345675 ^ Schmoe/Joe ^ ; LRC "
	Track 2: " ;12345675 01/91 ^ 1234 ^ (discriminate data) ; LRC "
	Track 3: " ;12345675 ^ 01/91 ^ 5 (discriminate data) ; LRC "

	Here's the decoding of the above information:
	Track 1: ";" = Beginning of the data character
	"B" = Field-Control Character: I believe this character
	tells the ATM what type of account (or status)
	the user has.
	"12345675" = This is the account number of the cardholder.
	"^" = Data-field seperator.
	"Schmoe/Joe" = Last/First name of cardholder.
	"^" = Data-field seperator.
	";" = End of data character.
	"LRC" = Longitude Redundancy Check (end of track character).

	Track 2: ";" = Beginning of data character
	"12345675" = Account number of the cardholder.
	"01/91" = Month/Year the card expires.
	"^" = Data-field seperator.
	"1234" = Process Identification Number (The cardholders 'password',
	I think... or it could be a number to verify the
	the transaction between the ATM and the Main Computer).
	"^" = Data-field seperator
	"(dscrmn. data)" = Discriminate Data. Not much is known exactly what is
	stored here. Perhaps Bank Identification data or
	bank account type (savings, checking?) ?
	";" = End of data character.
	"LRC" = Longitude Redundancy Check.

	Track 3: ";" = Beginning of data character.
	"12345675" = Account number of the cardholder.
	"^" = Data-field seperator.
	"01/91" = Month/Year the card expires.
	"^" = Data-field seperator.
	"5" = The crypting-digit. When the transaction request
	is sent to the main computer, it is encrypted.
	This digit tells which encryption-key is used.
	"(dscrmn. data)" = A duplicate of the discriminate data stored on
	Track 2.
	";" = End of data character.
	"LRC" = Longitude Redundancy Check.

	When the card is being processed the ATM tries to match the
	account number, expiration date and name stored on each track.
	The reason they duplicate data is for verification purposes. But,
	notice that the duplicate data is stored on different tracks, each
	having different recording densities. Once the information on the
	tracks are confirmed to match, the ATM compares them to the embossed
	information on the front-side. If all of the information matches
	then the transaction will proceed. If it doesn't match, then the card
	is considered to be damaged and the ATM will keep the card. It will
	give the cardholder a piece of paper instructing the user to notify
	the bank who issued his ATM-card so he can receive a replacement
	card in the mail (this process takes about 3 weeks).


	Now that you know how the ATM-system is designed and what information
	is kept where on the card, what "security defects" does this system
	contain ? I will outline 4 methods of attacking this system that
	have been tried (not by me!).

	1) Vandalization: If you want, you can break-in to the ATM.
	However, most ATM's contain 'sensor' devices which sound an
	alarm when this is tried. Therefore, if you're going to try
	this method I do not suggest using a hammer and chisel on the
	ATM because it will take 1/2 an hour to get the machine open
	and by that time the police will be there. You could try a
	much faster way, dynamite; but that might scatter the money
	all-over, making it hard to collect. Also, the bottom-half
	is where most of the money is stored (unless you happen to
	choose a machine that has issued all of its withdrawl-cash)
	so you'll want to break into the bottom-half of the ATM.

	In relation to this, you could wait outside the ATM for a
	valid-user to complete his withdrawl-transaction and mug him.
	As far as I know, the bank holds no responsibilty for placing
	the ATM in a 'secure' enviroment. However, usually they will
	have lights nearby and placed in 'reasonable' places where
	people need money (example: Grocery store) and where the chance
	of mugging is slim.


	2) Physical Penetration: There are several ways of doing this.
	If you have a stolen card, you could randomly try guessing his
	account-password. But, I feel this is a primitive method.
	If you try too many attempts at guessing the 'password',
	the ATM will return the card to you. But, your attempts
	might be recorded in the central computer; allowing the
	bank to decide whether to cancel that card... However,
	this has not been verified by me. If you do get a cash-card,
	you can make counterfeit-cards.

	A) Counterfiet ATM-cards: The same method for producing
	counterfiet credit cards applies to ATM-cards. If you
	have a valid ATM-card you can 'clone' it simply by embossing
	a blank-card with the same information. Copying the mag-
	netic strip is also easy. To do this, you place a blank
	strip of the magnetic tape on top of the valid magnetic
	strip. Then, using an iron on low-heat, gently rub the
	iron across the two strips for a few seconds. Lastly,
	peel the new strip apart from the valid one and you've
	got a copy of all the data from the valid ATM-card.

	B) Also, I've heard a case where some guys had a machine
	that could read and write to the magnetic strips (probably
	they were employees of a company that produces the ATM-cards).
	Using this machine, they were able to create and change
	existing data on ATM-cards (such as the expiration date
	so they could keep using the same card over a long period
	of time).

	In relation to this there are other devices available that
	can read and write to magnetic strips. Using your own
	microcomputer, you can buy a device that allows you to
	read and write to these magnetic strips. It looks
	similar to a disk drive. If you're interested in
	exploring this method, I'll suggest that you contact
	the following company:

	American Magnetics Corporation
	740 Watsoncenter Road
	Carson, California 90745
	USA

	213/775-8651
	213/834-0685 FAX
	910-345-6258 TWX

	C) WARNING: During each transaction attempted on an ATM a
	photo of the person requesting the transaction is taken.
	How long this film is stored is unknown, but it probably
	is different for each bank (unless there is a federal
	regulation regarding this). Also, it is possible that
	this is not done at all ATMs.

	3) "Insider" Theft: The above case also crosses over into this
	section. The biggest 'security leaks' in any company are
	its employees. This is also the easiest way to steal money
	from ATMs. The man who collects the deposits from the machine
	and inserts cash for withdrawls has the easiest and most
	open access to these machines. I was told that this person
	can easily steal money from ATMs and not be detected. Another
	person with access to these machines is the technician. The
	technician who fixes ATMs is the most-knowledgeable person
	about ATMs within the bank, therefore he should be a trust-
	worthy guy and receive a 'comfortable' salary.. otherwise
	he'll begin to collect 'retirement benefits' from the ATM
	and this may go undetected.

	However, I have heard of some embezzlement-cases involving ATMs,
	so I think it's not as easy as it seems. It's only common sense
	that a bank would account for every dollar of every transaction.
	Whether the accounting is done inside the ATM or the main
	computer doesn't make a difference... some form of accounting
	is probably done.

	4) Data-link Intercept: This method has been very successful. What
	you do is 'tap' into the wires that connect the ATM to the Main
	computer. By doing this you can intercept and send signals to
	the ATM. However, some 'inside information' is needed because
	the transmission is encrypted (refer to the Cryptography Digit
	stored on the magnetic strip). But, I think you don't need to
	know everything being transferred. You should need to know
	when to send the 'approval' signal to the ATM telling it to
	dispense its' cash. I read a case (it may be in Phrack World
	News; 1985?) where some guys netted $600,000 from various ATMs
	using this method. This seems to be one of the better, and
	more ingenious methods of stealing from these machines.


	The information in this file should be 'adequate' to introduce you
	to how ATMs work. How did I get this information? I went into a
	bank and inquired about the computer-technology of ATMs. The man
	who was responsible for the ATMs was a bureaucrat and actually knew
	very little about the 'guts' of ATMs. Luckily the ATM-technician
	was there that day and I agreed to buy him dinner later that evening.
	(Please refer to: "Insider" Theft and the principle of Company-Loyalty).
	During the dinner at "Toppers" (a neat 1950's Burgers/Milkshake/Beer
	restaurant) he provided me with Operation and Repair manuals for the
	ATMs. I feel this information is well-worth the $3.82 dinner and
	will be of some value to its' readers. Some good information was
	screened-out due to its 'delicate nature', but the information I've
	provided has been confirmed.


	+---------+
	] CREDITS ]
	+---------+
	The Mentor (Phrack #8, File #7; "Fun with Automatic Tellers")
	Deserted Surfer
	Hyudori
	Lex Luthor

	Please distribute this file in its complete form.

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