Seeing unauthorized charges on your credit card can be a headache. Removing these charges from your account and getting a replacement card isn’t fun, either.
The root cause of why you have unauthorized charges on your credit card can vary, as there are multiple types of credit card fraud.
Some of these fraudulent charges are part of what’s known as a BIN (bank identification number) attack. But what is that? And is there anything you can do to protect yourself?
A BIN attack is a type of credit card fraud where cybercriminals exploit the Bank Identification Number (BIN), The first six digits of your credit card, to generate and test valid credit card numbers for fraudulent transactions.
It uses brute-force computing to attempt to guess a valid combination of credit card number, expiration date and card verification value, or CVV, number.
While a person can attempt to guess one number at a time, a software program can attempt thousands of combinations in a matter of seconds. Once it finds a number that works, it can try other (similar) variations and then use those at online merchants — if other cards will have the same initial six digits.
Many of these purchase attempts are blocked without customers ever seeing any activity on their accounts. However, purchase “attempts from trusted merchants” are more difficult to block.
Ultimately, a BIN attack doesn’t depend on the type of card you have, nor does it need to get inside a company’s software. It’s simply trying to find a combination of numbers that will result in a successful transaction. Once it does, the fraudsters hope the affected cardmember won’t notice until the fraudsters can make additional purchases or cash withdrawals.
The importance of checking your credit cards regularly for fraudulent charges cannot be overstated. If you can detect problems as quickly as possible, you may prevent further unauthorized transactions.
It’s also important to understand who to contact if you do find unauthorized charges on your credit card: that is the issuing bank.