Although we don't have to worry much about viruses infecting our Linux machines, we do need to worry about sharing infected files with Windows users. ClamAV is a Free Open Source Software (FOSS) antivirus solution that can either that works pretty much the on your typical Windows workstation. The included freshclam utility allows you to update virus signatures.
Linux Malware Detect, which you'll often see abbreviated as either LMD or maldet, is another FOSS antivirus program that can work alongside ClamAV. (To save typing, I'll just refer to it as either LMD or maldet from now on.) As far as I know, it's not available in the repositories of any Linux distro, but it's still simple enough to install and configure. One of its features is that it automatically generates malware detection signatures when it sees malware...