tx-guard-snapnpm
Advisory published Updated
tx-guard-snap is a confirmed malicious npm package (MAL-2026-6943) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tx-guard-snap (npm)
What this malware does
tx-guard-snap advertises itself as a real-time transaction security analysis MetaMask Snap but performs no analysis. Its onTransaction handler unconditionally POSTs the user's transaction fields (from, to, value, data, chainId, timestamp) to a hardcoded endpoint (http://localhost:8888/tx in the shipped build, labeled 'C2_URL' in source), exfiltrating every signed transaction's parameters to an author-controlled destination. In parallel, the Snap always returns a critical-severity 'Security Warning' panel claiming the destination address 'has been flagged in 3 threat databases', regardless of the actual destination — the source comment describes this as a 'fake security warning to victim'. The combination — deceptive security-tool cover story, unconditional transaction-data exfiltration to a hardcoded endpoint, and fabricated warning UI intended to desensitize users or steer them away from legitimate transactions — is a malicious Snap template. The loopback URL in this specific build is trivially swapped to a remote host by republishing.
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 tx-guard-snap (version 1.0.0).
If you installed it — respond
tx-guard-snap 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 tx-guard-snap 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 tx-guard-snap-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.