Leak site not responding

Jsworm ransomware group

Jsworm 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.

Leak site statusOfflinenot answering

Tracked since—no dated record

Last activity—nothing recorded

Sectors observed—none stated

Who they are

JSWorm is a ransomware family that first appeared in May 2019 and is notable for undergoing multiple rebrands and evolutions, later appearing under names such as Nemty, Nefilim, Offwhite, Fusion, and Milihpen. Initially, it was distributed via malicious spam emails containing JavaScript files, hence the “JS” in its name. Later versions moved to targeted intrusions, leveraging compromised RDP services and vulnerable network appliances for initial access. JSWorm encrypts files using AES-256 encryption with RSA-2048 for key protection and appends campaign-specific extensions (e.g., .JSWORM, .Nemty, .Nephilim). The group adopted a double-extortion model in its later stages, stealing data before encryption and threatening to leak it via Tor-hosted sites. Its victimology spans various sectors worldwide, including manufacturing, energy, healthcare, and professional services. The continuous rebranding suggests an effort to evade detection, disrupt attribution, and maintain pressure on victims.

Descriptions are compiled from public reporting and vendor research. They describe how a group has historically operated and can lag its current behaviour; the status and timings above are our own.

Current status

Jsworm'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.

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

Industries this group has been observed going after, most common first.

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 Jsworm 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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