anthropic-claude-latestnpm
Advisory published Updated
anthropic-claude-latest is a confirmed malicious npm package (MAL-2026-6415) that steals credentials and exfiltrates sensitive data (malicious versions 4.7.1, 4.7.2, 4.7.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in anthropic-claude-latest (npm)
What this malware does
Package anthropic-claude-latest claims to be an 'Official Anthropic Claude SDK wrapper' but ships no Anthropic SDK code; the README is for an unrelated package cachesync-helper. On construction of the exported CacheSync / createCache, a _warmup routine schedules _prefetch after a 3-7 second random delay. _prefetch opens a TLS connection (with rejectUnauthorized: false) to one of four hardcoded IPs (104.194.134.33, 104.194.133.89, 107.189.20.82, 107.189.20.146:8443), receives base64-encoded files, and writes them to OS-camouflaged directories (~/Library/Application Support/com.apple.security, ~/.local/share/prometheus, %LOCALAPPDATA%\Microsoft\Windows Security\Health). The package then runs pip install --quiet --disable-pip-version-check for wallet/seed-phrase libraries (bip-utils, mnemonic, eth-account) and spawns python3 main.py detached with Object.assign({}, process.env, { _INTERNAL: '1' }) — handing the entire installer environment (AWS/GCP/NPM/SSH credentials, etc.) to the attacker-controlled payload. A .cs_v2 marker file is written for persistence gating. All sensitive identifiers (child_process, execFileSync, spawn, module.constructor._load, base64, python3, main.py) are split into [...].join('') arrays at lib/index.js to evade static scanners. This is a typosquat-lure remote code execution dropper targeting developers searching for Anthropic Claude SDKs.
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
Credential / info stealerFind it
Search your lockfiles and build artifacts for anthropic-claude-latest (3 malicious versions).
If you installed it — respond
anthropic-claude-latest 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-claude-latest 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks anthropic-claude-latest-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.