Blackbyte ransomware group
Blackbyte 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 1y ago.
Who they are
BlackByte ransomware was first observed in July 2021 and operates as a Ransomware-as-a-Service (RaaS). It uses a double-extortion model—encrypting victim files while exfiltrating sensitive data for publication on its Tor-based leak site. The ransomware is written in C# and uses AES-256 for file encryption, with keys protected by RSA public-key encryption. Early variants exploited the ProxyShell vulnerability in Microsoft Exchange servers for initial access, but later campaigns have leveraged phishing, malicious attachments, and vulnerable internet-facing systems. BlackByte appends extensions such as .blackbyte or .blackbyte2.0 to encrypted files and leaves ransom notes (BlackByte_restoremyfiles.txt) instructing victims to contact them via Tor. The group has targeted organizations worldwide, including critical infrastructure, manufacturing, and government sectors. In February 2022, the FBI and USSS released a joint advisory warning about BlackByte’s impact and offering detection signatures.
Current status
Blackbyte'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 1y ago (8 Jul 2025 17:43 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 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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