Cossy Ransomware
Cossy is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on December 1, 2018, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: Grafimatriux.
Quick facts
How Cossy ransomware works
File encryption patterns
Cossy modifies encrypted files using specific patterns to mark them as encrypted:
Ransom note and payment demands
After encrypting files, Cossy displays ransom notes demanding payment for file recovery:
notes/Как все эту шалашкину контору расшифровать.txt
notes/Крайне важная инфа.RSA-2048 файл
Technical indicators
Associated executable files
The following executable files are associated with Cossy ransomware:
- Cossy.exe
- Cossy.bin
- Attachment.rar
About this analysis
This Cossy 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 Cossy.
Last updated: December 30, 2025
Elastio detects Cossy inside your data and backups.
The Hunt Engine uses Deep File Inspection to identify Cossy 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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