GCVE-110-OSM-2026-13944

Malicious PyPI package containing an import-triggered, cross-platform downloader. On macOS it retrieves an x86-64 Mach-O backdoor that establishes an encrypted command channel, inventories the host, enumerates processes, and can retrieve, decrypt, drop, and execute an additional payload. The Windows branch also downloads and executes payloads, although its endpoint returned an empty response during verification. Importing the configuration module executes triple-Base64-obfuscated YAML through PyYAML UnsafeLoader. The decoded YAML launches platform-specific subprocesses that download and execute two payload copies. The recovered macOS payload is a command-loop backdoor using randomized form fields, Base64, AES-256-CBC, SHA-1 integrity checks, and distinct registration and command operation identifiers. A confirmed command collects kernel and process information. Another command streams encrypted chunks, recognizes a numeric termination marker, decrypts the reconstructed payload, writes it to a temporary path, marks it executable, and launches it detached. No package installation hook is required; execution occurs when the configuration module is imported. The downstream streamed payload remains unresolved.