Which versions of tree-sitter-forth are malicious?

The following npm versions of tree-sitter-forth are flagged malicious: 9999.99.99. Treat any of these as compromised.

How do I remediate tree-sitter-forth if I installed it?

tree-sitter-forth 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 tree-sitter-forth — how do I know if it already compromised me?

If tree-sitter-forth 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 tree-sitter-forth part of a known attack campaign?

Yes — tree-sitter-forth is associated with the IN-MAL-2026-007198 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 tree-sitter-forth across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for tree-sitter-forth (version 9999.99.99).

Malicious package

tree-sitter-forthnpm

Advisory published Jun 23, 2026Updated Jun 23, 2026

tree-sitter-forth is a confirmed malicious npm package (MAL-2026-6297) that steals credentials and exfiltrates sensitive data (malicious version 9999.99.99). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in tree-sitter-forth (npm)

MAL-2026-6297

Immediate action

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

npm uninstall tree-sitter-forth

What this malware does

Package is a dependency-confusion lure: it claims version 9999.99.99 with description 'npm 404 error referenced in AlexanderBrevig/tree-sitter-forth', engineered to win resolution when an internal build references a non-existent public package of this name. index.js is a hollow re-export (module.exports = require('tree-sitter-forth')) while postinstall.js fires the actual payload. On npm install, postinstall.js collects host identity (os.hostname(), Node/OS versions, package name+version), probes 16 CI provider environment variables, harvests GitHub workflow/repo/owner env vars, and reads the configured npm registry URL, then POSTs the bundle as JSON to https://ddactic-lab.online/sc/beacon (postinstall.js:48). A DNS-exfil fallback encodes the package slug, CI label, and a hash into a subdomain of b.ddactic-lab.online (postinstall.js:62 dns.lookup(...b.ddactic-lab.online)) to bypass HTTP-blocking egress proxies. The leaked data — internal CI provider, private registry URL, GitHub repo/workflow names — is reconnaissance material for follow-on dependency-confusion attacks against the victim's internal infrastructure.

Malicious versions

1 flagged

9999.99.99

Indicators of compromise (SHA-256)

16f52e13ffb66b20f7c3dca7022e8115dbce1f39264638d38b73d6488e4cbf27

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for tree-sitter-forth (version 9999.99.99).
If you installed it — respond
tree-sitter-forth 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 tree-sitter-forth 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. tree-sitter-forth on npm has been identified as a malicious package (version 9999.99.99 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-007198

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks tree-sitter-forth-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

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