First, you'll have to explain much more about the complaints, e.g.:
# the forum URL
# what measures you have to prevent untrusted users posting on your forum
# what details your users provide to back up the virus claims
# what you have done to confirm their claim
# why you believe they have good reason for their complaint
and so on...
then there is a chance of being able to tell you why you are getting the complaints.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.