boxy-constantsnpm
boxy-constants is a confirmed malicious npm package (MAL-2026-13033) that steals credentials and exfiltrates sensitive data (malicious version 35.2.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in boxy-constants (npm)
What this malware does
On require of the package, index.js loads shim.js which reconstructs attacker-controlled hostnames from split-string arrays (Cloudflare Workers subdomains such as oob-worker.cf100-41.6.workers.dev and *.dl.wel1.ru), selects an OS/arch-specific URL for linux_x64/linux_arm64/darwin/win32, fetches an unsigned, unhashed binary via https.get, writes it to /var/tmp/.cache<hex> on POSIX or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmods 0755, and detaches it via spawn("/bin/sh",["-c", fp+" &"]) or cmd /c start. A DNS-TXT base64 channel provides a fallback host-resolution path. A marker file '.analytics_state' implements cooldown-based execution suppression, and a stealth logger writes empty strings to stderr. Decoy filenames (dotnet_diag_,.cache_) and 'analytics/telemetry' naming disguise the dropper. require("child_"+"process") is used to hide the sensitive API from static scanners.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for boxy-constants (version 35.2.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging boxy-constants across your stack and pipelines.
If you installed it — respond
boxy-constants 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-constants was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks boxy-constants before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks boxy-constants-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.