whs4_deunpm
whs4_deu is a confirmed malicious npm package (MAL-2026-11070) that opens a backdoor for remote access (malicious versions 1.0.0, 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in whs4_deu (npm)
What this malware does
package.json declares a postinstall hook that runs index.js on npm install. On execution, index.js POSTs the installer's absolute __filename path (which typically embeds the OS username and directory layout), Node.js version, and platform/architecture to a hardcoded Discord webhook at discord.com/api/webhooks/1530599209269465319/. The destination is not caller-configurable, the behavior is undocumented, and the webhook URL literal is split via string concatenation to evade trivial grep for the full endpoint. The package ships no other functionality consistent with its name; the install-time beacon is the sole observable behavior.
The OpenSSF Package Analysis project identified 'whs4_deu' @ 1.0.1 (npm) as malicious.
It is considered malicious because:
- The package communicates with a domain associated with malicious activity.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for whs4_deu (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging whs4_deu across your stack and pipelines.
If you installed it — respond
whs4_deu 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 whs4_deu 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 whs4_deu 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
- OpenSSF: Package Analysis · finder
Detect & block this
O3 blocks whs4_deu-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.