Ransomware Research
Mespinoza Ransomware
Mespinoza is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on November 1, 2019, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: Mespinoza, Pysa, Mespinoza Doxware.
Quick Facts
- Ransomware Family
- Mespinoza
- First Seen
- November 1, 2019
- Known Aliases
- MespinozaPysaMespinoza Doxware
How Mespinoza Ransomware Works
File Encryption Patterns
Mespinoza modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..locked..pysa..newversionRansom Note and Payment Demands
After encrypting files, Mespinoza displays ransom notes demanding payment for file recovery:
Readme.READMERansom message:
notes/Readme.README
Note locations:
EveryFolderTechnical Indicators
Associated Executable Files
The following executable files are associated with Mespinoza ransomware:
51.exe628637.exe1.exeMespinoza.exe
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About This Analysis
This Mespinoza 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 Mespinoza.
Last updated: July 30, 2025