Description Summary
Renewed surge through Q4 2025; distinctive VHD-based evasion.
Threat Actor
RaaS (85/15 split, no upfront fee); 'Good Day'/ARCrypter lineage; runs payload from virtual hard disks (VHD) + Neshta file infector for self-propagation.
Technical Indicators
Encryption Extension
Not publicly reported
Encryption Algorithm
HC-128 with keys via Curve25519 + SHA-512
Ransom Note Name
Not publicly reported
Targeted Industries
Cross-sector (per leak-site victim telemetry)
First Seen
RaaS since February 2024
Last Seen
Active (Q4 2025 surge)
Geographical Location
Global / not publicly profiled
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 |