For a good while now, gamers have been menaced by the ransomware TeslaCrypt, which seeks out game-related files and locks them up, demanding payment in exchange for access. But in an unexpected twist, the hackers behind the virus have closed up shop after more than a year of activity, releasing the master key and giving victims a way to unlock their files.

Security firm ESET says it contacted the makers of the ransomware after the group announced plans to stop operations. ESET asked for the master decryption key and, however improbably, the TeslaCrypt hackers then made the key public. Using that key, the firm has now released a tool for decrypting files hit by TeslaCrypt.

"If you have been infected by one of the new variants (v3 or v4) of notorious ransomware TeslaCrypt and encrypted files files had the extensions .xxx, .ttt, .micro, .mp3 or left unchanged, then ESET has good news for you," the firm says in an announcement.

On the page formerly hosting the payment site, the malware makers posted the key along with a message: "we are sorry!"

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