Ethersphere, the team behind Swarm, said an attacker with its release-bot credentials published a fake version 13.3.0 of the @ethersphere/bee-js npm package. It went live at 00:09 UTC on 9 November 2026 and was removed at about 01:25 UTC. Ethersphere said a matching loader, a small script that fetches and runs more code, also shipped in Swarm Desktop v0.56.2 at 00:36 UTC. That release was later removed and replaced by v0.56.3. Researcher cgsec.dev wrote on 15 November that the desktop release stayed marked latest for nearly eight hours after the npm removal. In that state, the app's auto-updater could offer it.
Ethersphere said the script ran on every install, fetched its second stage from the attacker's server, and could send different code to different installs. The payload researchers captured took the Swarm node's wallet key and set up a remote-access tool. The sources do not say how many people installed either version. They also do not give the exact time the desktop release came down. Ethersphere warns that finding none of the known files does not prove a machine is clean, since other payloads may have been served.
cgsec.dev says the npm package carried valid provenance and the Mac app was signed with the project's own certificate, because the attacker held the bot's identity. Those checks passed. Ethersphere advises teams to search lockfiles for 13.3.0 and pin bee-js to 13.2.0. It says any machine that ran the install with scripts enabled should be treated as compromised.