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supplychainattack.orgSupply chain attack incident catalog
resolvedcritical

Malicious code in yper (PyPI)

Attacker distributed 900+ malicious packages via PyPI, including yper, which installed malicious browser extensions designed to manipulate clipboard contents and replace cryptocurrency wallet addresses. The campaign was identified and documented by the OpenSSF malicious-packages project.

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Disclosed
Last updated
Blast radius
900+ malicious packages distributed; targets local browsers and cryptocurrency wallets
Ecosystems
PyPI
Attack vectors
Compromised package
Affected entities
  • yperPyPI package containing malicious code

An attacker distributed over 900 malicious packages through the Python Package Index (PyPI), with yper being one of the identified packages. These packages contained code that installed malicious browser extensions on infected systems.\n\nThe malicious extensions were designed to intercept and manipulate clipboard data, specifically targeting cryptocurrency wallet addresses. When users copied wallet addresses, the extension would replace them with attacker-controlled addresses, enabling theft of cryptocurrency transfers.\n\nThe campaign was identified and documented by the OpenSSF's malicious-packages project (MAL-2023-2465). The incident represents a large-scale supply chain attack leveraging PyPI's package distribution mechanism to reach end users.

Indicators of compromise

Packages
  • yper

Remediation

  • Remove yper and any other suspicious packages from affected systems
  • Audit installed Python packages for unexpected or unfamiliar dependencies
  • Scan systems for malicious browser extensions, particularly those with clipboard manipulation capabilities
  • Review recent cryptocurrency transactions for signs of address replacement attacks
  • Monitor PyPI for similar malicious package campaigns and maintain updated blocklists
  • Use package verification tools and dependency scanning in development workflows

Sources

  1. GitHub Advisory GHSA-jvv2-4pwq-g9mw · GitHub Advisory Database

Cite this entry

"Malicious code in yper (PyPI)." supplychainattack.org, Supply Chain Attack Incident Catalog. Disclosed July 21, 2026; last updated July 21, 2026. https://supplychainattack.org/incident/malicious-code-in-yper-pypi-14ili0

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