Blacklock Ransomware

Description Summary

BlackLock is a rebranded version of another ransomware group known as Eldorado. It has since become one of the most active extortion syndicates in 2025, heavily targeting technology, manufacturing, construction, finance, and retail sectors.

Threat Actor

Rebrand of El Dorado; RaaS; infrastructure breached by Resecurity in early 2025.

Technical Indicators

Encryption Extension
Not publicly reported
Encryption Algorithm
ChaCha20 + RSA-OAEP (Golang, cross-platform)
Ransom Note Name
Not publicly reported
Targeted Industries
Construction, Real estate (broad)
First Seen
~September 2024 (rebrand of El Dorado)
Last Seen
Declining (post early-2025 infra breach)
Geographical Location
Global

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