The open source antivirus program you might be referring to could be
Clamwin. I used it many years ago. It did seem rather accessible but
those who know me will know that we need to consider the program's
overall ability to protect us as much as, if not more, than its level of
screen reader accessibility.

David Goldfield,
Assistive Technology Specialist

Feel free to visit my Web site
WWW.DavidGoldfield.Info