Swift warns of hack attack on bank

Swift, an inter-bank messaging system, was embroiled in one of the largest cyber bank thefts

Swift, the inter-bank messaging system embroiled in one of the largest cyber heists in history, warned customers that hackers have struck again, attacking a commercial bank client that it didn't name.

The details of a second hack follow a cyber theft in February, when more than $80 million was stolen from Bangladesh's account at the Federal Reserve Bank of New York. Swift warned users last month that it was aware of several similar attacks.

This time, the hackers used malware to target a PDF reader used by the customer to check its statement messages, Swift said on Friday. A Swift spokesman declined to reveal the name of the bank, but a UK-based security firm, BAE Systems, said in a blog post that it believes the second victim is a commercial bank in Vietnam. BAE isn't directly involved in the investigation, but analysed malware samples uploaded to public repositories from locations in both Bangladesh and Vietnam and found a match.

BAE said details in the code from the Bangladesh and Vietnam hacks also match a third breach, the devastating 2014 attack on Sony Pictures, which US officials attributed to North Korea. BAE said the match indicates that the same hackers may be behind all three attacks: "This adds a significant lead to the investigation," BAE said in its post. An earlier report by the company probing the hack for the bank came to a different conclusion, according to a person briefed on the investigation.

"Forensic experts believe this new discovery evidences that the malware used in the earlier reported customer incident was not a single occurrence, but part of a wider and highly adaptive campaign targeting banks," Swift said in a statement.

In its warning, Swift said customers using PDF reader applications to check confirmation messages should take particular care.

Investigators examining the theft from Bangladesh's central bank have uncovered evidence of three hacking groups - including a group linked to North Korea - inside the bank's network but say it was an unidentified group that pulled off the heist, people familiar with the bank's internal investigation said earlier this week. The attempted theft of almost $1 billion has prompted central banks around the globe to review defenses against hackers, along with calls by US government officials to beef up security.