Ransomware Research
Katyusha Ransomware
Katyusha is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on October 1, 2018, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: Sysfrog.
Quick Facts
- Ransomware Family
- Katyusha
- First Seen
- October 1, 2018
- Known Aliases
- Sysfrog
How Katyusha Ransomware Works
File Encryption Patterns
Katyusha modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..katyusha..sysfrogPrefixes added to encrypted files:
[sysfrog@protonmail.com]Ransom Note and Payment Demands
After encrypting files, Katyusha displays ransom notes demanding payment for file recovery:
_how_to_decrypt_you_files.txtRansom message:
notes/_how_to_decrypt_you_files.txt
Note locations:
ProgramDatahow_to_decrypt.txtRansom message:
notes/how_to_decrypt.txt
Note locations:
ProgramDataRootDiscsTechnical Indicators
Associated Executable Files
The following executable files are associated with Katyusha ransomware:
katyushakatyusha.exeKatyushaRansomware.binTrojan.Ransom.Katyusha.exeKatyushaRansomware.exeRansomware Katyusha.exe604.json2018-10-14 Katyusha.exeKatyusha.exemyfile.exeoutdrprov.dllKatyusha.ransom.exe
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About This Analysis
This Katyusha 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 Katyusha.
Last updated: July 30, 2025