ClamAV is an open source (GPL) antivirus engine designed for detecting Trojans, viruses, malware and other malicious threats.
It provides a high performance mutli-threaded scanning daemon, command line utilities for on demand file scanning, and an intelligent tool for automatic signature updates.
The core ClamAV library provides numerous file format detection mechanisms, file unpacking support, archive support, and multiple signature languages for detecting threats. The core ClamAV library is utilized in Immunet 3.0, powered by ClamAV, which is a fast, fully featured Desktop AV solution for Windows.
ClamAV 0.97 brings many improvements, including complete Windows support (all major components compile out-of-box under Visual Studio), support for signatures based on SHA1 and SHA256, better error detection, as well as speed and memory optimizations.