strict-engine-peernpm
strict-engine-peer is a confirmed malicious npm package (MAL-2026-5898) that opens a backdoor for remote access (malicious versions 1.0.0, 22.18.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in strict-engine-peer (npm)
What this malware does
On npm install, the package's preinstall hook (preinstall: node index.js in package.json) executes index.js, which reads the installer's project directory via process.env.INIT_CWD, takes its basename as safeProjectName, and POSTs a JSON payload containing that name and a timestamp to a hardcoded callback URL https://deepbounty.dd06-dev.fr/cb/d9b7e171-33a4-49c7-aa79-c95794030d3b. The package self-describes as a 'Security PoC for Bug Bounty' / 'Harmless dependency confusion PoC', and the name strict-engine-peer is consistent with squatting an internal/private package name on the public npm registry. Any developer or build system that resolves this package — typically by accident, via dependency confusion against an internal package of the same name — silently discloses the existence and name of an internal project to the third-party endpoint. The 'research' framing does not change the installer-side impact: unconsented network beacon at install time, leaking organizational metadata to an attacker-controlled host.
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 strict-engine-peer (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging strict-engine-peer across your stack and pipelines.
If you installed it — respond
strict-engine-peer 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 strict-engine-peer 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 strict-engine-peer 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 strict-engine-peer-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.