Blackbyte-Crux ransomware group
Blackbyte-Crux 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 3mo ago.
Who they are
Crux is a newly identified ransomware variant active since July 2025, which claims affiliation with the established BlackByte ransomware group. It implements a double‑extortion model—encrypting files (with the .crux extension) and threatening data leak via a Tor-based portal. A distinctive feature of Crux is its execution flow: it initiates via svchost.exe, cmd.exe, and bcdedit.exe to disable Windows recovery, followed by rapid file encryption. The ransomware has been confirmed in at least three incidents across sectors including agriculture, education, professional services, media, and nonprofits, in both the U.S. and U.K. Ransom notes consistently follow the naming pattern crux_readme_[random].txt.
Current status
Blackbyte-Crux'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 3mo ago (7 Jun 2026 21:21 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 Blackbyte-Crux 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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