Helldown
Helldown is a ransomware group with a financial motive, tracked by Brandefense. It targets 13 sectors, including Government and Technology, in 22 countries, including the United States and the United Kingdom. It uses 27 MITRE ATT&CK techniques and exploits 2 known CVEs.
- Techniques
- 27
- Exploited CVEs
- 2
- Record updated
Who They Target.
About Helldown.
Helldown is an aggressive ransomware group first documented in August 2024, known for exploiting Zyxel firewall vulnerabilities to gain initial access and conducting large-scale data exfiltration averaging 70 GB per victim, targeting IT services, telecommunications, manufacturing, and healthcare primarily in the US.
Last updated Sep 30, 2026. Compiled by Brandefense technologies from structured threat intelligence and reviewed by Brandefense analysts. Techniques follow the MITRE ATT&CK framework.