
They may not even have changed the password, which means you could be logging in normally while all this is happening unaware that there’s a problem at all, until your friends start complaining. Someone guessed your password, or stole it somehow to login to your email account.

Someone has gained access to your email account and is sending email from it. Someone is sending email from your account, probably to email addresses that are in the contact list or address book of that account. You didn’t indicate what leads you to believe that your email account has a virus, however if you’re situation is like any of the hundreds of reports I see every week, it’s very simple: Besides, if they did they’d be all over it and would resolve it extremely rapidly.

While it’s theoretically possible, it’s so incredibly rare compared to other possibilities that it’s honestly not worthy wasting a moment even thinking about.
