Kairos Ransomware

Description Summary

Data-extortion (no encryption); ~50 victims under 'Kairos V2' by Aug 2025.

Threat Actor

Data extortion; selective exfil via RClone (targets PDFs/Office documents).

Technical Indicators

Encryption Extension
N/A — no encryption (exfiltration + extortion)
Encryption Algorithm
N/A
Ransom Note Name
N/A
Targeted Industries
Healthcare, Manufacturing, Business services
First Seen
13 November 2024
Last Seen
Active (Kairos V2 ~50 victims by Aug 2025)
Geographical Location
US (assessed Eastern-European/Russian origin)

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