eacq-authnpm
Advisory published Updated
eacq-auth is a confirmed malicious npm package (MAL-2026-13208) that executes malicious code on install (malicious version 35.4.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in eacq-auth (npm)
What this malware does
index.js exports a benign TokenManager facade but silently require('./_bootstrap') in a try/catch on load. bootstrap.js selects a platform-specific asset, downloads an unverified binary from hardcoded Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev) — with a DNS-TXT chunked-fetch fallback under *.dl.wel1.ru — writes it to /tmp or %TEMP% under a disguised name (e.g. dotnet_diag,.cache_), chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe start /b. Destination hostnames are reconstructed by array.join to evade static string matching. Executes at require() time, so a normal npm install + any downstream import runs the fetched binary on the installer host.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for eacq-auth (version 35.4.8).
If you installed it — respond
Remove eacq-auth from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If eacq-auth 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 eacq-auth-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.