Belsen Group ransomware group
Belsen Group is one of the extortion operations we watch continuously. This page covers what is known about the group and the current state of its leak site, which we last saw change 2y ago.
Who they are
aka Belesn Group.
Belsen Group emerged in January 2025 as a data broker and leak-focused threat actor, not engaging in ransomware encryption. Their first major action involved publishing sensitive configuration files, VPN credentials, and IP addresses for over 15,000 Fortinet FortiGate firewalls—data likely stolen through exploitation of CVE‑2022‑40684. The group began by sharing the data freely to establish credibility, before shifting to monetized access and offering sales of network access to high-value targets such as major banks and an East African airline. Their activities place them firmly in initial access brokerage, targeting confidential infrastructure details for sale.
Current status
Belsen Group's leak site is not answering. Sites go dark for infrastructure trouble, a deliberate quiet period, or a takedown, and a good number return weeks later under the same name, so the entry stays on the list either way.
The last change we recorded on it was 2y ago (12 Mar 2025 20:03 UTC).
Which organisations this group has named, and when, is part of the SINON platform rather than this page. Create an account to search it, or to be told automatically if a name you care about turns up.
Sectors targeted
This group does not state an industry on its site, so we have nothing reliable to report. Most crews are opportunistic rather than sector-specific in any case — they hit what they can reach.
Watching for your name
If Belsen Group posts your company, a supplier or a subsidiary, you want to hear it from us rather than from a journalist. SINON checks these sites continuously and alerts on the names you give it.
Start monitoring