Chaos ransomware group
Chaos 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 17h ago.
Who they are
Chaos is a rapidly evolving Ransomware-as-a-Service (RaaS) group first observed in early 2025. It is considered distinct and unaffiliated with the Chaos Ransomware Builder that originated around 2021. Known for highly aggressive double-extortion operations, Chaos targets organizations across multiple platforms—Windows, ESXi, Linux, and NAS—with fast, configurable encryption mechanisms and optional partial-file targeting for stealth. Attackers gain access through vulnerabilities, phishing, or brokered credentials, then encrypt files while threatening to leak or destroy stolen data. Notable incidents include the breach of Optima Tax Relief, in which the group exfiltrated 69 GB of sensitive data before encrypting systems.
Current status
Chaos's leak site is answering our checks. That does not mean the group is actively posting — plenty of sites stay up for months with nothing new on them — but the infrastructure is live.
The last change we recorded on it was 17h ago (4 Sep 2026 19:17 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.
Leak site capture
Watching for your name
If Chaos 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.
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