eacq-payform-corenpm
Advisory published Updated
eacq-payform-core is a confirmed malicious npm package (MAL-2026-11538) that executes malicious code on install (malicious version 20.3.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in eacq-payform-core (npm)
What this malware does
On require() of the package, index.js loads _vendor.js which selects a platform-specific endpoint, fetches an opaque binary over HTTPS from Cloudflare Workers subdomains whose hostnames are reconstructed at runtime by joining split string fragments (e.g. "oob-worker.cf102-ba"+"f.w"+"orkers.dev"), with a DNS TXT chunked-base64 fallback channel (c.<domain> for chunk count, then N.<domain> TXT queries reassembled via Buffer.from(parts.join(""), "base64")). The fetched bytes are written under a disguised name (dot-file or dotnet_diag masquerade) in /var/tmp or %TEMP%, chmod 0o755 on POSIX, then detached-spawned via /bin/sh -c or cmd.exe. Package advertises itself only as a 'platform core' with no legitimate need for platform-detected binary execution. Host strings are deliberately fragmented to evade static analysis; a rate-limit marker is written to /tmp/.analytics_state or %TEMP%\analytics_state.
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
Malicious packageFind it
Search your lockfiles and build artifacts for eacq-payform-core (version 20.3.6).
If you installed it — respond
Remove eacq-payform-core 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-payform-core 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-payform-core-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.