The developers behind the Shade ransomware on Monday announced that they ceased operations and publicly released decryption keys to let their victims recover files for free.
Also referred to as Troldesh and Encoder.858, Shade has been present on the malware landscape since 2014. Updated with backdoor capabilities in 2016, the Trojan became one of the most prevalent threats last year, when it was observed targeting over 340 file extensions for encryption (using AES 256).
Shade was mainly distributed via phishing emails carrying malicious ZIP archives. Last year, security researchers discovered that it was the most prevalent piece of malware being stored in hidden “well-known” directories of HTTPS sites.
Now, the ransomware’s authors say they actually stopped distributing the malware at the end of last year, and that they now decided to completely close shop and release over 750,000 decryption keys, along with their decryption utility.
“Now we made a decision to put the last point in this story and to publish all the decryption keys we have (over 750 thousands at all). We are also publishing our decryption soft; we also hope that, having the keys, antivirus companies will issue their own more user-friendly decryption tools,” the ransomware authors noted on GitHub.
The developers also claim that other data related to the operation, including the Trojan’s source code, has been destroyed.
“We apologize to all the victims of the trojan and hope that the keys we published will help them to recover their data,” they say.
Additionally, the ransomware authors published instructions on how victims can recover their files even without the help of dedicated decryption tools.
Victims are advised to wait for anti-malware companies to release official decryption tools for files encrypted by Shade, but there’s no information available yet on when such utilities will become available.