Навалом, (и все шлюзовые ;)
http://www.microsoft.com/isaserver/partners/contentsecurity.mspx
CA's eTrust Antivirus Gateway for ISA Server
BitDefender for Microsoft ISA Server offers antivirus protection for web traffic, including protection for data received through webmail.
GFI DownloadSecurity for ISA Server
TrendMicro InterScan WebProtect works in real-time as a filter for viruses and malicious code
Symantec™ Web Security for Microsoft® Internet Security and Acceleration (ISA) Server