Chaco Ransomware
Chaco is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on June 1, 2025, this ransomware has been actively targeting systems worldwide.
Quick facts
How Chaco ransomware works
File encryption patterns
Chaco modifies encrypted files using specific patterns to mark them as encrypted:
Ransom note and payment demands
After encrypting files, Chaco displays ransom notes demanding payment for file recovery:
notes/readmebuster.txt
notes/nuyww298c.png
Technical indicators
Associated executable files
The following executable files are associated with Chaco ransomware:
- ChacoRansomware.exe
- System.exe
About this analysis
This Chaco 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 Chaco.
Last updated: December 30, 2025
Elastio detects Chaco inside your data and backups.
The Hunt Engine uses Deep File Inspection to identify Chaco 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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