Back in February, hackers stole $81 million from the Bangladeshi central bank’s account at the Federal Reserve Bank of New York. The fraudulent transfer request likely came through the SWIFT system, a messaging network used by more than 11,000 financial institutions to communicate and issue transfer instructions. It appears that hackers used compromised credentials to access the network and malware to cover their trail so they wouldn’t be immediately detected.

Click the player above to hear more about the attack and its implications.