North Korean hackers the culprit behind Asian bank heists: report

A bank in the Philippines was also targeted.

The group which stole $81 million from Bangladesh's central bank and attempted to steal over $1 million from Vietnam's Tien Phong Bank have also been linked to targeted attacks against a bank in the Philippines, security firm Symantec said in a report.

The report revealed that some of the malware used in the attacks share code similarities with those utilized by a threat group known as Lazarus. The group has been linked to a string of aggressive attacks since 2009, the largest of which was an attack against Sony Pictures Entertainment. The FBI concluded that the North Korean government was responsible for this attack.

Symantec has identified three pieces of malware which were being used in limited targeted attacks against the financial industry in South-East Asia: Backdoor.Fimlis, Backdoor.Fimlis.B, and Backdoor.Contopee.

"Symantec believes distinctive code shared between families and the fact that Backdoor.Contopee was being used in limited targeted attacks against financial institutions in the region, means these tools can be attributed to the same group," the report said.