boxy-test-makernpm
Advisory published Updated
boxy-test-maker is a confirmed malicious npm package (MAL-2026-13091) that steals credentials and exfiltrates sensitive data (malicious version 35.8.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in boxy-test-maker (npm)
What this malware does
On require() of the package, index.js loads ext.js which assembles C2 hostnames from split string fragments (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, with a DNS-TXT covert-channel fallback to *.dl.wel1.ru), downloads a platform-specific binary, writes it to a disguised path under /var/tmp or %TEMP% (filenames such as.cache<hex> or dotnet_diag_<hex>.exe), chmods 0755, and spawns it detached via /bin/sh -c or cmd.exe. A dedup stamp file named analytics_state and opt-out-style environment variable checks are used as cover. Hostnames are reconstructed at runtime via array.join("") to evade static string matching. Requiring or installing this package executes attacker-controlled native code on the host.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for boxy-test-maker (version 35.8.2).
If you installed it — respond
boxy-test-maker 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-maker 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-maker-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.