You all are assuming it was a brute force attack. AFAIK it could be keys strolen from your hard drive. Blockchain stores keys on your computer, they are not responsible for keeping the keys safe.
I think that maybe a very good point. I have now used every sort of scan I can find and none of them picked up any trojans, worms keyloggers or remote access attempts. Also, maybe this isn't important but this happened on my Blockchain.info wallet after I had changed the settings to send an email to my gmail account for every transaction. I'm at a loss to explain it but I'm not using Blockchain.info until I know eveything is ok again. I ran spybot and it found nothing either. I checked for extra phoney system file mimics, like csrss.exe. I've never had a problem before with any online service on this laptop
One thing extra thing I've done now is to lock the wallet to a fixed IP, (it's in the Blockchain settings) so it can't be accessed from any other IP, all well and good as long as my IP doesn't change. Otherwise, it will be a huge hassle.
