Supply chain · pip · High

Malicious pip package 'npp-ml' impersonates Notepad++, delivers ADExplorer

Threat Engine Auto-Feed · data current as of 2026-10-12

A malicious package, 'npp-ml' version 0.1.7, was identified in the pip ecosystem. It masquerades as a Notepad++ distribution but instead deploys ADExplorer, an Active Directory analysis tool. This supply-chain attack poses a critical risk to systems that installed the package.

  • Package: pip / npp-ml
  • Affected versions: = 0.1.7
  • Severity: critical
  • Reach: ~980/wk
  • Exposure: 70/100 (High)

What happened — Malicious package

The 'npp-ml' package (version 0.1.7) was published to PyPI with malicious intent. It falsely claims to be a Notepad++ distribution but actually installs ADExplorer, a legitimate tool used for Active Directory analysis. This constitutes an impersonation attack with clearly malicious objectives.

How the attack works

This is a software supply-chain attack where a malicious actor publishes a package under a deceptive name to a public registry. Users who install this package inadvertently execute the attacker's code, which in this case involves deploying an unexpected and potentially unauthorized tool. The attack relies on users mistaking the malicious package for a legitimate or desired software component.

Who's exposed

Profiles most at risk

  • Development teams using the pip ecosystem
  • Organizations with CI/CD pipelines that pull unpinned or latest dependencies from PyPI
  • Security teams responsible for monitoring Active Directory environments

Conditions that increase exposure

  • Unpinned dependencies in project manifests (e.g., requirements.txt without specific versions)
  • Lack of lockfiles (e.g., poetry.lock, Pipfile.lock) to ensure reproducible builds
  • Use of internal package mirrors that do not vet upstream packages
  • Automated build processes that install dependencies without human review

Blast-radius scenarios

  • Installation of ADExplorer on developer workstations or build servers, potentially providing an attacker with reconnaissance capabilities within an Active Directory environment.
  • Compromise of systems where the package was installed, leading to further malicious activity if ADExplorer is misused or if the initial deployment mechanism has additional backdoors.
  • Increased attack surface due to the presence of an unauthorized tool on critical systems.

What to do (defensive)

Detect

  • Scan project dependency lists for 'npp-ml' version 0.1.7.
  • Review system logs and installed software inventories for unexpected installations of ADExplorer or related artifacts.
  • Monitor network traffic for unusual connections originating from systems that installed the package.
  • Utilize software composition analysis (SCA) tools to identify known malicious packages in your dependency tree.

Contain

  • Isolate any systems identified as having installed 'npp-ml' version 0.1.7.
  • Block 'npp-ml' from being downloaded from internal package managers or proxies.
  • Review and revoke any credentials or tokens that may have been present on compromised systems.
  • Implement strict dependency pinning and lockfiles across all projects.

Remediate

  • Uninstall 'npp-ml' and any associated components (including ADExplorer) from all affected systems.
  • Perform a thorough forensic analysis on compromised systems to identify the full extent of the breach.
  • Rebuild affected systems from trusted images if compromise cannot be fully confirmed or remediated.
  • Update dependency management practices to include vetting of new packages and regular security audits.

Frontier verdict — High

Prioritize immediate detection and removal of 'npp-ml' due to its critical severity and potential for Active Directory reconnaissance.

Sources

For detection-engineering and awareness only · point-in-time · not security advice · sourced from the GitHub Advisory Database.