Crosslock ransomware group
Crosslock 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 3y ago.
Who they are
CrossLock ransomware was first observed in April 2023, targeting an IT services firm in Brazil using a double‑extortion approach—encrypting data and threatening to leak it publicly. Written in Go, it uses a hybrid encryption scheme combining ChaCha20 for file encryption with Curve25519 for key protection. Victims see their files renamed with the .crlk extension and ransom notes titled ---CrossLock_readme_To_Decrypt---.txt. The malware includes advanced techniques like Event Tracing for Windows (ETW) bypass and process mimicking (e.g., Cybereason processes) for stealth. It was publicly tracked until July 2023, after which activity (and its leak site) went offline.
Current status
Crosslock'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 3y ago (28 Jul 2023 00:13 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 Crosslock 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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