It said that hackers have become more “sophisticated” in launching attacks.
Global bank transfer system SWIFT has confirmed that cyber criminals continued their attacks after stealing $81m from the Bangladesh central bank in February this year.
Hackers have become more “sophisticated” in launching the attacks, according to a SWIFT official and an undisclosed letter sent by the messaging network to banks across the world.
In a letter sent to banks on 2 November, which was seen by Reuters, SWIFT cautioned over growing threats to its systems.
SWIFT said: “The threat is very persistent, adaptive and sophisticated – and it is here to stay.”
The attacks and new hacking methods highlights that the network, which handles trillions of dollars in fund transfers daily, remains vulnerable to cyber thefts, the publication reported.
The letter warned that hackers are deploying new tactics to attack local bank systems.
One of the sophisticated methods being used by the attackers included software that enables technicians to access computers to offer technical support.
SWIFT’s letter said: “We unfortunately continue to see cases in which some of our customers’ environments are being compromised by attackers.”
Without disclosing details on the attacks, the letter said that the thieves send fraudulent payment instructions through the SWIFT network.
SWIFT’s customer security programme head Stephen Gilderdale declined to reveal the accounts or value of the funds that have been hacked recently.
Gilderdale said: “In all of these cases attackers are suspected of trying to replicate the modus operandi of the Bangladesh attackers.”
He added that some of banks’ antivirus software had been found to contain malware.
In other cases, software provided by SWIFT to its customers was able to alert the network of an “attempted manipulation” of a bank’s system.
Gilderdale said: “In 80% 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.”
SWIFT is the primary communications channel for financial institutions engaged in correspondent banking around the world, transmitting messages relating to payments, securities, treasury and trade between financial institutions.