An odd new pattern of credit card fraud emanating from Brazil and targeting U.S. financial institutions could spell costly trouble for banks that are just beginning to issue customers more secure chip-based credit and debit cards.
Over the past week, at least three U.S. financial institutions reported receiving tens of thousands of dollars in fraudulent credit and debit card transactions coming from Brazil and hitting card accounts stolen in recent retail heists, principally cards compromised as part of the breach at Home Depot.
The most puzzling aspect of these unauthorized charges? They were all submitted through Visa and MasterCard‘s networks as chip-enabled transactions, even though the banks that issued the cards in question haven’t even yet begun sending customers chip-enabled cards.
The most frustrating aspect of these unauthorized charges? They’re far harder for the bank to dispute. Banks usually end up eating the cost of fraud from unauthorized transactions when scammers counterfeit and use stolen credit cards. Even so, a bank may be able to recover some of that loss through dispute mechanisms set up by Visa and MasterCard, as long as the bank can show that the fraud was the result of a breach at a specific merchant (in this case Home Depot).
However, banks are responsible for all of the fraud costs that occur from any fraudulent use of their customers’ chip-enabled credit/debit cards — even fraudulent charges disguised as these pseudo-chip transactions.
CLONED CHIP CARDS, OR CLONED TRANSACTIONS?
The bank I first heard from about this fraud — a small financial institution in New England — battled some $120,000 in fraudulent charges from Brazilian stores in less than two days beginning last week. The bank managed to block $80,000 of those fraudulent charges, but the bank’s processor, which approves incoming transactions when the bank’s core systems are offline, let through the other $40,000. All of the transactions were debit charges, and all came across MasterCard’s network looking to MasterCard like chip transactions without a PIN.
The fraud expert with the New England bank said the institution had decided against reissuing customer cards that were potentially compromised in the five-month breach at Home Depot, mainly because that would mean reissuing a sizable chunk of the bank’s overall card base and because the bank had until that point seen virtually no fraud on the accounts.
“We saw very low penetration rates on our Home Depot cards, so we didn’t do a mass reissue,” the expert said. “And then in one day we matched a month’s worth of fraud on those cards thanks to these charges from Brazil.” Continue reading →