DHAKA • Hackers who stole US$101 million (S$137 million) from Bangladesh's central bank stalked its computer systems for almost two weeks beforehand, according to an interim investigation report seen by Bloomberg.
Prepared for the Bangladesh Bank by cyber security firms FireEye and World Informatix, the assessment offers a tantalising glimpse into how cyber criminals can use the banks' own systems against them.
The cyber companies say the thieves deployed malware on servers housed at the central bank to make payments seem genuine. The report cast the unidentified hackers as a sophisticated group which sought to cover their tracks by deleting computer logs as they went.
Before making transfers, they sneaked through the network, inserting software that would allow re-entry. It was the sort of thorough operation often mounted by nation-state hackers, according to the report, but FireEye's intelligence unit believes the group, which it has been tracking for some time, is criminal.
The heist exposed weaknesses in systems, sparked a dispute between Bangladesh's central bank and its finance ministry, and cost the central bank governor his job less than five months before he planned to retire.
The hackers sent US$81 million from the Bangladesh Bank's account in New York to the Philippines, and another US$20 million to Sri Lanka. The Federal Reserve Bank of New York blocked transactions worth another US$850 million.
A bank in Sri Lanka stopped and returned the cash, while the money in the Philippines is still missing.
"Malware was specifically designed for a targeted attack on Bangladesh Bank to operate on Swift Alliance Access servers," the interim report said.
Swift is a member-owned cooperative that provides international codes to facilitate payments between banks globally.
Mr Charlie Booth from Brunswick Group, a corporate advisory firm that represents Swift, said: "We reiterate that the Swift network itself was not breached."
Bangladesh yesterday formally sought assistance from the US Federal Bureau of Investigation to track down the crooks.