Hackers targeting the SWIFT interbank system are getting more sophisticated, according to a previously undisclosed letter the organization sent to banks worldwide.
The letter warns banks around the world of an increasing threat to their systems since a February hack of Bangladesh’s central bank sent $81 million into the ether. The success of the big hack — and the ongoing war increasingly advanced attackers are waging on the system — is turning up heretofore unknown vulnerabilities in the messaging network responsible for trillions of dollars in daily payments.
“The threat is very persistent, adaptive and sophisticated — and it is here to stay,” SWIFT said in the November letter to client banks, seen by Reuters.
Central and commercial banks use SWIFT — and have seen a “meaningful” uptick in attacks. Those hits result in stolen funds about 20 percent of the time since the February heist, Stephen Gilderdale, head of SWIFT’s Customer Security Programme, told Reuters in an interview on Thursday. SWIFT has revealed three such hacks since the attack in February, though none of those resulted in any reported lost funds.
The letter also sought to inform SWIFT’s banking partners of how attacks are evolving on their network.
“We unfortunately continue to see cases in which some of our customers’ environments are being compromised” by thieves who then send fraudulent payment instructions through the SWIFT network. This was the method of attack in Bangladesh, noted the letter, without further explanation.
SWIFT’s Gilderdale declined to provide further details about more recent attacks or to name victims or amounts stolen. Asked how many heists had been attempted, he said only that it was “a meaningful number of cases.”
“In all of these cases attackers are suspected of trying to replicate the modus operandi of the Bangladesh attackers,” he added.
The news isn’t all bad, according to Gilderdale, as the system is evolving along with the hackers.
“In 80 percent of the cases that we are aware of and where we have completed investigations, a fraud has not actually ended up taking place,” he said.
“I personally am very pleased with the progress that we are making,” he added.