Whats happened is someone has read your password off your machine, and then logged into your account online elsewhere and is generating spam through your online account, and using your address book.
Sometimes just changing your password and security questions are enough to stop it, but my ex-wife was plagued recently with repeats of this on her AOL even though she changed her password three times
The problem was that the "ghost sender" wasn't logging off and so wasn't affected by the password changes - which would only kick in when they logged off and back in again
We only cured it after we got AOL to sever all logins to her account at their end, forcing all users to log in, simultaneously with them imposing yet anotther password reset. That fixed it, no more problems
This particular case was with AOL, but any webmail service could be hacked in this way
An important thing to note as well is that I sanitized the machine after the first sign of problems and made sure it was clean, however the damage had been done. They'd nicked the logon credentials beforehand - possibly when she logged into her mail through her fathers computer.
Remember - you are at risk on ANY machine you use, not just your own
Last edited by Milo Minderbinder; 15th May 2012 at 13:25.