pfp-block-mobile-past-meetup-listnpm
Advisory published Updated
pfp-block-mobile-past-meetup-list is a confirmed malicious npm package (MAL-2026-12409) that opens a backdoor for remote access (malicious version 20.5.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in pfp-block-mobile-past-meetup-list (npm)
What this malware does
On require() of pfp-block-mobile-past-meetup-list, index.js loads ext.js which runs a bootstrap routine. It fetches a platform-specific binary via https.get from one of three Cloudflare Workers hosts (oob-worker.cf1-03-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS-TXT chunked fallback resolved through tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, and win.dl.well1.site. The fetched payload is written to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755, and spawned detached via /bin/sh -c or cmd.exe /c start. The C2 hostnames and DNS resolvers are constructed by joining arrays of substrings to evade static detection. Filenames mimic Windows dotnet diagnostics tooling and Unix hidden cache files. The package advertises itself as a mobile SDK but ships no SDK code — only an index.js stub and the _ext.js dropper. Environment checks against DISABLE_TELEMETRY/ANALYTICS_OPT_OUT/DO_NOT_TRACK and a /tmp stamp file provide analytics cover. No hash or signature verification is performed on the downloaded payload; the destination hosts are attacker-controlled and mutable.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for pfp-block-mobile-past-meetup-list (version 20.5.1).
If you installed it — respond
pfp-block-mobile-past-meetup-list establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If pfp-block-mobile-past-meetup-list was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks pfp-block-mobile-past-meetup-list-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.