Federal prosecutors are investigating North Korea’s possible role in the theft of $81 million from the central bank of Bangladesh in what security officials fear could be a new front in cyberwarfare.

The United States attorney’s office in Los Angeles has been examining the extent to which the North Korea government aided and abetted the bold heist in February 2016, according to a person briefed on the investigation who was not authorized to speak publicly.

In the theft, the attackers, using a global payment messaging system known as Swift, were able to persuade the Federal Reserve Bank of New York to move money from the Bangladesh bank to accounts in the Philippines. The Swift system is used by some 11,000 banks and companies to transfer money from one country to another.

In the months that followed the Bangladesh heist, it was disclosed that cyberthieves had also attacked banks in Vietnam and Ecuador using Swift.