Ransomware Research
Hentai Oniichan Ransomware
Hentai Oniichan is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on September 1, 2020, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: Berserker, King Engine.
Quick Facts
- Ransomware Family
- Hentai Oniichan
- First Seen
- September 1, 2020
- Known Aliases
- BerserkerKing Engine
How Hentai Oniichan Ransomware Works
Targeted Files
https://www.vmray.com/cyber-security-blog/hentai-oniichan-ransomware-berserker-malware-analysis-spotlight/
File Encryption Patterns
Hentai Oniichan modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..HOR..docmRansom Note and Payment Demands
After encrypting files, Hentai Oniichan displays ransom notes demanding payment for file recovery:
WARNING.htmlRansom message:
notes/WARNING.html
Note locations:
Desktopreadmerecovery.txtRansom message:
notes/readmerecovery.txt
Note locations:
DesktopREADME_RECOVERY.txtRansom message:
notes/README_RECOVERY.txt
Note locations:
UserFoldersTechnical Indicators
Associated Executable Files
The following executable files are associated with Hentai Oniichan ransomware:
recent_invoice_view.exeinvoice_view.exeFatality_DIed.dllPandora.dllFatality DIed.dll
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About This Analysis
This Hentai Oniichan 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 Hentai Oniichan.
Last updated: July 30, 2025