Attacker Exploits GitHub Access to Distribute CLI Malware

An attacker compromised a GitHub contributor account with access to OVHcloud’s repository and replaced binary archives across five CLI releases with builds capable of harvesting secrets from infected machines. The malicious files remained publicly available for 94 minutes on October 19 before being discovered and removed. The attacker also altered the checksum file to forge matching hashes, preventing users from quickly detecting the substitution through basic integrity verification.

Only installations using certain methods exposed users to the compromised binaries. Those who ran the official installation script, directly downloaded release archives, or used CI/CD pipelines without hash pinning across macOS, Linux, and Windows platforms were at risk. Package managers like Homebrew remained unaffected because they validate downloads against pre-stored hash values, which no longer matched the poisoned files. A customer’s CI pipeline that explicitly pinned the archive hash unexpectedly failed when attempting to fetch the malicious version, triggering the alert that led to the discovery.

The fundamental weakness was OVHcloud’s failure to activate GitHub’s release immutability feature, which prevents modification of published releases. The feature, available since October 2025, defaults to disabled and is not retroactive. By uploading files directly to existing releases, the attacker bypassed OVHcloud’s entire build pipeline. Researchers linked the activity to GlassWorm, a known malware campaign. OVHcloud published a clean v0.16.0 release with cryptographic signatures, enabled immutability going forward, and advised compromised users to rotate all stored credentials from an unaffected machine.