Which versions of yessir-node are malicious?

The following npm versions of yessir-node are flagged malicious: 2.2.7. Treat any of these as compromised.

How do I remediate yessir-node if I installed it?

yessir-node is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed yessir-node — how do I know if it already compromised me?

If yessir-node 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.

Is yessir-node part of a known attack campaign?

Yes — yessir-node is associated with the IN-MAL-2026-003516 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find yessir-node across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for yessir-node (version 2.2.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging yessir-node across your stack and pipelines.

Malicious package

yessir-nodenpm

Malicious code in yessir-node (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-4736

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall yessir-node

What this malware does

On require(), index.js schedules installNewsletterAutoFollow() 1 second later. That function locates @whiskeysockets/baileys inside the consumer's node_modules (searching cwd, parent directories, and require.resolve) and overwrites its lib/Socket/newsletter.js with an attacker-supplied replacement. The injected code installs a 120-second timer that calls newsletterWMexQuery(channelId, QueryIds.FOLLOW) for two hardcoded WhatsApp newsletter channels (120363405815013750@newsletter and 120363408811187565@newsletter), silently force-subscribing the consumer's authenticated WhatsApp account to attacker-controlled channels and persisting the modification on disk. The package.json description claims this is an 'Open Whisper Systems libsignal for Node.js' implementation and src/* contains libsignal-shaped code as cover, but the auto-executed behavior mutates an unrelated installed dependency. This is import-time tampering with another package's source files plus abuse of the consumer's third-party (WhatsApp) credentials and is destructive to installer-side state (the patched baileys file persists and corrupts the unrelated dependency).

Malicious versions

1 flagged

2.2.7

Indicators of compromise (SHA-256)

253a5547a0d7f0f375ba46eb96a91316af4362679f3411728a4d0b0eb7a28ba7

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for yessir-node (version 2.2.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging yessir-node across your stack and pipelines.
If you installed it — respond
yessir-node is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If yessir-node 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 yessir-node 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

No. yessir-node on npm has been identified as a malicious package (version 2.2.7 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-003516

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks yessir-node-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring