isa 2006 error

[[OUPA]MrNutz]

hi peeps..

customer had mabezat.a worm , sys admin ran nod32 on isa/exchange....error afterwards on all pcs when browsing the web:

http://i210.photobucket.com/albums/bb147/jannie40/NetworkAccessMessage.jpg

any ideas what can be done / checked? proxy service has been stopped/restarted ect

thx