What is Zenis ransomware
Zenis encrypts files on the infected computer, renaming them to Zenis-[2 random characters].[12 random characters], and leaves ransom notes (Zenis-Instructions.html) in folders with encrypted files. Zenis ransomware has been analyzed by security researchers, and Michael Gillespie (@demonslay335 on Twitter) has found a weakness in the ransomware that allows decryption of files. That weakness is not released publicly lest the ransomware developers find out and fix it. Users who wish to decrypt their files for free can contact Michael Gillespie (however that won’t be quick: there are a lot of victims, and the decryption itself is time-consuming). It is quite possible that Zenis developers will find the weakness and release a new, more secure version of ransomware in the future; in that case you can use this guide to try recovering your files by other methods.