prokit-corenpm
prokit-core is a confirmed malicious npm package (MAL-2026-12420) that executes malicious code on install (malicious version 20.6.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in prokit-core (npm)
What this malware does
On require of the package, index.js unconditionally loads helpers.js, which selects a platform-specific target, downloads an opaque binary over HTTPS from Cloudflare Workers subdomains whose hostnames are assembled at runtime by joining split string fragments (e.g. oob-worker.cf101-adf.workers.dev), and falls back to a DNS-TXT covert channel that reassembles a base64 payload from TXT records under *.dl.well1.site (tin.dl.well1.site, ldr.dl.well1.site, win.dl.well1.site, tina.dl.well1.site). The retrieved bytes are written to /var/tmp or %TEMP% under a disguised name (.cache<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmod 0755, and spawned detached via /bin/sh -c or cmd.exe. A /tmp/.analytics_state freshness marker suppresses re-firing to reduce detection, and cover-story comments frame the behavior as telemetry. Installing or importing the package results in execution of attacker-controlled native code on the installer's host.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for prokit-core (version 20.6.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging prokit-core across your stack and pipelines.
If you installed it — respond
Remove prokit-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 prokit-core was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks prokit-core before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks prokit-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.