Supply chain · pip · High

Malicious 'proxycer' package in PyPI uses typosquatting for data exfiltration

Threat Engine Auto-Feed · data current as of 2026-09-05

The 'proxycer' package (version 0.1.0) in the PyPI ecosystem is malicious, designed to collect basic user information upon import. It leverages typosquatting to trick users into unintentional installations, posing a limited but critical supply-chain risk.

  • Package: pip / proxycer
  • Affected versions: = 0.1.0
  • Severity: critical
  • Reach: unknown
  • Exposure: 65/100 (High)

What happened — Typosquatting

A malicious package named 'proxycer' (version 0.1.0) was published to PyPI. This package is designed to exfiltrate basic system data, such as IP address and username, when imported. The advisory indicates it is part of a campaign utilizing typosquatting to achieve unintentional installations.

How the attack works

This is a supply-chain attack leveraging typosquatting, where a malicious package is named similarly to a legitimate one to trick developers into installing it by mistake. Once installed and imported into a project, the package executes its malicious code, in this case, collecting and exfiltrating basic system information.

Who's exposed

Profiles most at risk

  • Developers and development teams using the PyPI ecosystem
  • Organizations with automated build systems or CI/CD pipelines that pull dependencies from PyPI
  • Anyone who might mistype a package name during installation and inadvertently install 'proxycer'

Conditions that increase exposure

  • Projects that do not pin dependency versions, potentially pulling the malicious 'proxycer==0.1.0'
  • Lack of a robust lockfile (e.g., requirements.txt with hashes, poetry.lock) to ensure deterministic builds
  • Reliance on internal mirrors that might not filter out known malicious packages
  • Human error in typing package names during manual installation

Blast-radius scenarios

  • If 'proxycer' is installed and imported, an attacker gains access to basic system information (IP, username) from the compromised environment.
  • The exfiltrated data could be used for reconnaissance, aiding in further targeted attacks against the affected system or organization.

What to do (defensive)

Detect

  • Scan dependency trees for 'proxycer==0.1.0' in any project using PyPI.
  • Monitor network traffic for unexpected outbound connections from build environments or applications that recently added new PyPI dependencies.
  • Review package installation logs for 'proxycer' or similar suspicious package names.

Contain

  • Immediately remove 'proxycer==0.1.0' from all affected environments and projects.
  • Block 'proxycer' from being downloaded from PyPI at the network perimeter or through package managers.
  • Isolate any systems where 'proxycer' was installed and imported to prevent further data exfiltration or potential lateral movement.

Remediate

  • Update all project dependencies to use pinned versions and maintain strict lockfiles to prevent accidental installation of new malicious versions.
  • Implement automated dependency scanning tools to identify known malicious packages in CI/CD pipelines.
  • Educate developers on typosquatting risks and best practices for verifying package authenticity before installation.

Frontier verdict — High

Prioritize immediate detection and removal of 'proxycer' due to its critical severity and data exfiltration capabilities via typosquatting.

Sources

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