OhNo! Ransomware
OhNo! is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on August 1, 2017, this ransomware has been actively targeting systems worldwide.
Quick facts
How OhNo! ransomware works
File encryption patterns
OhNo! modifies encrypted files using specific patterns to mark them as encrypted:
Ransom note and payment demands
After encrypting files, OhNo! displays ransom notes demanding payment for file recovery:
notes/note.txt
notes/wallpaper.jpg
Technical indicators
Associated executable files
The following executable files are associated with OhNo! ransomware:
- Google Chrome
- Defender.exe
- Google Chrome.exe
- ChromeBTCExtension.exe
- Malware (38).exe
About this analysis
This OhNo! 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 OhNo!.
Last updated: December 30, 2025
Elastio detects OhNo! inside your data and backups.
The Hunt Engine uses Deep File Inspection to identify OhNo! 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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