A slew of files leaked online yesterday are said to indicate the US National Security Agency (NSA) monitored global bank transfers.
The documents and computer code, released by a hacking group called the Shadow Brokers, reportedly show the NSA accessed the Swift interbank messaging system, which could have allowed it to covertly monitor money flows among some banks based in the Middle East and Latin America.
The release included computer code that could be adapted by criminals to break into Swift servers and monitor messaging activity, said Shane Shook, a cybersecurity consultant who has helped banks investigate breaches of their Swift systems.
Although some records bear NSA seals, their authenticity has yet to be confirmed. The NSA has not yet commented on the leak.
The Swift network allows banks to move money around the world and the leaked files indicate one of its major bureaus, EastNets, may have been hacked. Shadow Brokers spreadsheets seemed to list banks that had been breached with data-gathering software, also known as "implants".
However EastNets, which is based in Dubai, denied it had been hacked in a statement, and said the assertion was "totally false and unfounded".
Criminals stole millions of dollars from Bangladesh's central bank after Swift was targeted by hackers last year.
"The release of these capabilities could enable fraud like we saw at Bangladesh Bank," Shook said.
In response, Swift has said there is no evidence that the main Swift network had ever been accessed without authorisation.
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Programmes for attacking various versions of the Windows operating system were also published.
Former NSA contractor Edward Snowden has dubbed the NSA's alleged activity as the "Mother of All Exploits":
The Mother Of All Exploits escaped from an NSA laboratory and is wrecking the internet. https://t.co/K1RqJeYIW5— Edward Snowden (@Snowden) April 14, 2017