It's not just Amiga sites (although you forgot ClassiAmiga that has also been hit).
Lots of sites are getting hacked in recent days, and not just vBulletin, but also WordPress, Joomla, and lots of others including popular ecommerce sites.
It's a random, 'carpet bombing' style of attack. A.org isn't safe from this either.
WotTheFook aka Merlin