IP Address Spoofed? How To Fix
If it is explicitly just your IP Address and not a subnet that is detected as attacking,
It is very likely it happened actually from your IP address.
Moreover, it is not easy to spoof a public IP address on the internet.
Where do you get your IP address from?
If it is allocated from a broadband/DSL subscription,
it could very well be rotating over other subscribers.
Yet, it would be interesting to know which virus has been attracted towards the stackoverflow servers like this.
Could you have something like the firefox ReloadEvery addon going berserk?