Thanks so much to HN for helping me with this! You have no idea how grateful I am for the support I get here.
These are blogs and my first thought was to get rid of all comments and close access to any future comments - a daunting job for one blog which is 6 years old - in case something got through my filters via comments
But the sites that were infected were the same two sites that I have on twitter in my profiles ( 2 identities, 2 profiles, 2 sites listed).
In any case, this seems too much like a coincidence to me.
I just read yesterday something about false tweets being sent out through twitter and a way someone can make them appear as coming from you, with links to malware. Crazy stuff.