Cheers ransomware group
Cheers 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
Cheers is a Linux-based ransomware variant observed starting in May 2022, engineered specifically to target VMware ESXi servers. The malware was developed from leaked Babuk ransomware source code and leverages the SOSEMANUK stream cipher combined with ECDH key exchange for encryption. It terminates all running virtual machines before renaming and encrypting log files and VM-related extensions—like .vmdk, .vmsn, and .vswp—appending a .Cheers extension. A ransom note titled "How To Restore Your Files.txt" is dropped per directory. The ransomware is attributed to the Chinese-affiliated group BRONZE STARLIGHT (also known as Emperor Dragonfly, DEV-0401), which has previously deployed other strains like Rook, NightSky, and Pandora. Cheers targets a range of industry sectors, with confirmed victims across healthcare, finance, logistics, and manufacturing.
Current status
Cheers'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 17:45 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 Cheers 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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