As many as 12 banks may have been hacked through the SWIFT network in a manner similar to the Bangladesh Bank theft where $81 million was stolen using fake SWIFT messages. Quoting a source close to the probe, Bloomberg Technology said security firm FireEye has been hired to investigate the reported breaches.

There is no confirmation that the banks, most of which are in Southeast Asia, have lost money.

Meanwhile, Symantec has claimed that a Philippines bank was breached by the same attackers who hit the Bangladesh central bank. Similar tools were used in the 2014 attack on Sony Pictures, Symantec researchers say.

SWIFT warns of more bank breaches being reported. “This is a big deal, and it gets to the heart of banking,” said CEO Gottfried Leibbrandt. “Banks that are compromised like this can be put out of business.”

SWIFT is working with members on increasing security between them.

Read full report at Bloomberg Technology.