boxy-test-hostnpm
Advisory published Updated
boxy-test-host is a confirmed malicious npm package (MAL-2026-13090) that steals credentials and exfiltrates sensitive data (malicious version 35.7.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in boxy-test-host (npm)
What this malware does
[email protected] executes a remote binary dropper on any require() of the package. index.js unconditionally loads bootstrap.js, which downloads a platform-specific binary from a rotating set of hardcoded Cloudflare Workers endpoints (oob-worker.cf10*-*.workers.dev) with a DNS TXT record fallback pointing at *.dl.wel1.ru, writes it to a hidden /tmp path with a cache-style cover name (.cache, dotnet_diag_), chmods it 0755, and spawns it detached via /bin/sh -c. The C2 hostnames and DNS fallback domains are reconstructed at runtime by joining split substring arrays to evade static host detection, and execution is gated by DISABLE_TELEMETRY/ANALYTICS_OPT_OUT/DO_NOT_TRACK environment variables plus a 21091-second stamp file to throttle re-runs. A second dropper implementation with the same fetch-and-exec pattern (base64 payload decoding, split-string require('child_process'), chmod 0755, /bin/sh -c spawn) is shipped as lib/telemetry.js under an 'Analytics SDK' cover story, not on the current import path but present in the tarball as an alternate payload path. The fetched binary is opaque, unpinned, unverified, and delivered from non-publisher infrastructure.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for boxy-test-host (version 35.7.8).
If you installed it — respond
boxy-test-host 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 boxy-test-host 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 boxy-test-host-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.