Babuk Ransomware

Description Summary

Babuk Ransomware is a sophisticated ransomware compiled for several platforms. Windows and ARM for Linux are the most used compiled versions, but ESX and a 32bit old PE executable were observed over time. as well It uses an Elliptic Curve Algorithm (Montgomery Algorithm) to build the encryption keys.

Threat Actor

Closed group; Windows, Linux/ESXi and ARM builds. Full source code leaked, spawning Babuk2, Rook, RA World, Nokoyawa and others.

Technical Indicators

Encryption Extension
.babyk / .babuk / variant-specific
Encryption Algorithm
Elliptic Curve (Curve25519/Montgomery) + ChaCha8/AES
Ransom Note Name
How To Restore Your Files.txt
Targeted Industries
Cross-sector (incl. Washington DC Police)
First Seen
January 2021
Last Seen
2021 (source/builder leaked Sept 2021; basis for many variants)
Geographical Location
Worldwide

MITRE ATT&CK Matrix

Tactic TTP Technique Name
Impact x 2 T1486 Data Encrypted for Impact
T1490 Inhibit System Recovery
Exfiltration x 1 T1567 Exfiltration Over Web Service (leak site)
Initial Access x 2 T1190 Exploit Public-Facing Application
T1078 Valid Accounts