CalcBoxLitePyPI
CalcBoxLite is a confirmed malicious PyPI package (MAL-2026-15488) that opens a backdoor for remote access (malicious version 1.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in calcboxlite (PyPI)
What this malware does
setup.py and calcboxlite/init.py both invoke a top-level _report() function that reads getpass.getuser() and socket.gethostname() and POSTs them as JSON to a hardcoded remote collector at https://k4m2qhx7ptv9nzcr3bwe8syd6ljfa0gu1.oast.invalid/collect. The beacon fires automatically on pip install and again on every import calcboxlite, so consumers in sandboxed builds, CI runners, REPLs, or downstream libraries all transmit installer identity to the endpoint. The destination host is unrelated to any advertised calculator functionality and is characteristic of an out-of-band interaction collector used for identifying vulnerable installers.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for CalcBoxLite (version 1.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging CalcBoxLite across your stack and pipelines.
If you installed it — respond
CalcBoxLite establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If CalcBoxLite 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 CalcBoxLite 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 CalcBoxLite-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.