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
How Hentai Oniichan ransomware works
File encryption patterns
Hentai Oniichan modifies encrypted files using specific patterns to mark them as encrypted:
Ransom note and payment demands
After encrypting files, Hentai Oniichan displays ransom notes demanding payment for file recovery:
notes/WARNING.html
notes/readmerecovery.txt
notes/README_RECOVERY.txt
Technical indicators
Associated executable files
The following executable files are associated with Hentai Oniichan ransomware:
- recent_invoice_view.exe
- invoice_view.exe
- Fatality_DIed.dll
- Pandora.dll
- Fatality DIed.dll
About this analysis
This Hentai Oniichan ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery, helping organizations defend against and recover from ransomware attacks like Hentai Oniichan.
Last updated: December 30, 2025
Elastio detects Hentai Oniichan inside your data and backups.
The Hunt Engine uses Deep File Inspection to identify Hentai Oniichan across live data, replicated data, and backups. If this family is in your environment, Elastio finds it before encryption completes. Run a scan against your recovery points to confirm.
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