Grisoft AVG is recommended by Kim Komando and some of the techies at my ISP. Its free version runs under Win9x on, and also runs under Linux (but not server OS's).
H+BEDV Datatechnik's AntiVir free version runs under Win9x on, but not Linux or server versions. They struggled for years to get to the gold standard of reliability but achieved it about a year ago.
ALWIL's avast! 4.0 (free home version) is also a Windows 9x+ product and has done well recently in stringent tests. They also have a PDA version (both Palm OS and WinCE/Pocket PC) for not very much money, that looks for the small d/b of PDA-specific malware.
Just for info.
Would any of these have protected that site, in this case?