Clam AntiVirus is an anti-virus toolkit for Unix. The main purpose of
 this software is the integration with mail servers (attachment
 scanning). The package provides a flexible and scalable
 multi-threaded daemon in the clamav-daemon package, a command-line
 scanner in the clamav package, and a tool for automatic updating via
 the Internet in the clamav-freshclam package. The programs are based
 on libclamav, which can be used by other software.
 .
 For programs written using the libclamav library. Libclamav may be used to add
 virus protection into software. The library is thread-safe, and automatically
 recognizes and scans archives. Scanning is very fast and most of the time
 not noticeable.