Which versions of anthropic-shared-logger are malicious?

The following npm versions of anthropic-shared-logger are flagged malicious: 8.0.5. Treat any of these as compromised.

How do I remediate anthropic-shared-logger if I installed it?

anthropic-shared-logger 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 anthropic-shared-logger — how do I know if it already compromised me?

If anthropic-shared-logger was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Is anthropic-shared-logger part of a known attack campaign?

Yes — anthropic-shared-logger is associated with the IN-MAL-2026-003657, IN-MAL-2026-003656, RLMA-2026-04926, RLUA-2026-06061 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 anthropic-shared-logger across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for anthropic-shared-logger (version 8.0.5).

Malicious package

anthropic-shared-loggernpm

Advisory published May 21, 2026Updated Sep 1, 2026

anthropic-shared-logger is a confirmed malicious npm package (MAL-2026-4479) that steals credentials and exfiltrates sensitive data (malicious version 8.0.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in anthropic-shared-logger (npm)

MAL-2026-4479

Immediate action

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

npm uninstall anthropic-shared-logger

What this malware does

This package impersonates Anthropic's internal namespace and self-describes as 'Full RCE PoC - Alex Birsan Style'. Its package.json declares a postinstall hook that, on every npm install, fetches the installer's public IP from api.ipify.org, runs id || ver && whoami && hostname via child_process.exec, and POSTs the hostname, current working directory, USERDOMAIN/COMPANY environment variables, IP address, and command output to a hardcoded Interactsh OOB endpoint at lszakfghwnvxspyfcmaabd1css99rnq3w.oast.fun over plain HTTP. The combination of namespace impersonation, automatic install-time shell execution, and host reconnaissance exfiltration to attacker-controlled out-of-band infrastructure is a canonical Birsan-style dependency confusion attack. Any build system that mis-resolves this name to the public registry leaks identity and host data to the attacker, enabling targeted follow-on compromise.

Malicious versions

1 flagged

8.0.5

Indicators of compromise (SHA-256)

754f7dc4855ecb1df012814bf5ec92a861958b7af0027d88d0a2cb918793cdce

e54ef50a83e2f379965286ed404d16ca3389a9ce5c8593718ef4e6f307cc6084

d7eb27d7306bba73ccc540f8b24d6b5b1a7ec3e5875240e9e1f1a36b85da1c1e

0b586996c40c96903c002f3280f3257e4814f86846b5fba1ff7683d93c04bbb0

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for anthropic-shared-logger (version 8.0.5).
If you installed it — respond
anthropic-shared-logger 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 anthropic-shared-logger was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. anthropic-shared-logger on npm has been identified as a malicious package (version 8.0.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-003657IN-MAL-2026-003656RLMA-2026-04926RLUA-2026-06061

References

Credits

Amazon Inspector · finder
ReversingLabs · finder

Detect & block this

O3 blocks anthropic-shared-logger-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

Explore

All malware advisories How O3 detects malware Vulnerability database