Endurance ransomware group
Endurance 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
Endurance is a destructive ransomware variant first observed in 2023, developed and operated by the threat actor known as IntelBroker (also referred to as Butler Spider). Rather than encrypting files for decryption, it functions primarily as a data wiper, overwriting file contents, appending randomized filenames, and then deleting the files altogether. The source code for the malware was intentionally made public by the operator, indicating its use as both a tool and a statement. Endurance was used in high-profile breaches, including targeting government agencies, large enterprises, and telecommunications providers.
Current status
Endurance'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 (1 Jun 2023 20:07 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 Endurance 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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