Over 280 million documents were also encrypted.

A new research by ESET reveals that the TorrentLocker ransomware has hit around 40,000 PCs, mainly targeting European countries, in addition to Canada, Australia and New Zealand.

The Win32/Filecoder.Dl family of ransomware locks down users’ computers and then encrypts documents, pictures and other files and demands payment to retrieve access.

ESET’s latest research also revealed that the hackers encrypted over 280 million documents.

Only 570 of the overall 40, 000 victims’ paid the Bitcoin ransom to retrieve access to their files, netting hackers between $292,700 and $585,401.

ESET Canada researcher Marc-Etienne Leveille said: "We believe the actors behind TorrentLocker are the same as those behind the Hesperbot family of the banking Trojan malware."

"Moreover, with TorrentLocker, the attackers have been reacting to online reports by defeating Indicators of Compromise used for detection of the malware and changing the way they use Advanced Encryption Standards (AES) from Counter mode (CTR) to Cipher block chaining mode (CBC) after a method for extracting the key stream was disclosed."

The security firm also noted that TorrentLocker victims will not be able to reclaim all their documents by integrating an encrypted file and its plain text to retrieve the key stream.