Email was hacked; what to do?
I am running version 10.8.5 on an iMac 27" (2011 model) and recently had the hard drive replaced. I noticed I was not getting emails and checked the email setup to find someone else's address in my incoming mail window. I put in my correct address and it changed back to the hacked address as soon as I opened Apple Mail. I deleted all info for this account and am using internet mail for the time. I need some advise for what to do. Is there some software that can remove this virus or do I need to take it in for cleaning. I am using "Bitdefender" anti-virus, but it obviously didn't stop the hack. Any advise would be helpful.
Flegal
iMac, OS X Mountain Lion (10.8.5), New hard drive 4-15-15