Ransomware Research
Zyklon Ransomware
Zyklon is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on May 1, 2016, this ransomware has been actively targeting systems worldwide.
Quick Facts
- Ransomware Family
- Zyklon
- First Seen
- May 1, 2016
How Zyklon Ransomware Works
Targeted Files
https://www.acronis.com/en-us/blog/posts/serpent-pretends-be-octopus-new-step-zyklon-ransomware-evolution/ https://www.hybrid-analysis.com/sample/61764600d8fb7f84d6f578a72b409aa7dd7f1c3fb5705fb2792d8459e87726f2?environmentId=100 Protected with ConfuserEx Requires C&C
File Encryption Patterns
Zyklon modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..zyklon..srpxRansom Note and Payment Demands
After encrypting files, Zyklon displays ransom notes demanding payment for file recovery:
/\bREADME_TO_RESTORE_FILES_[A-Za-z0-9]{3}\.html\b/Ransom message:
notes/README_TO_RESTORE_FILES_o6W.html
Note locations:
UserFoldersRootDiscs/\bREADME_TO_RESTORE_FILES_[A-Za-z0-9]{3}\.txt\b/Ransom message:
notes/README_TO_RESTORE_FILES_o6W.txt
Note locations:
UserFoldersRootDiscsTechnical Indicators
Associated Executable Files
The following executable files are associated with Zyklon ransomware:
Octopus6612683490_2604543229_download.zp.exeSerpent.exeurlref_http185.183.99.24update.zpupdate.zp
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About This Analysis
This Zyklon ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery solutions, helping organizations defend against and recover from ransomware attacks like Zyklon.
Last updated: July 30, 2025