brain wallets
Were the stolen coins in one?
I use a brain wallet to do my mining and when I want to cash out, NORMALLY I would just import the private key into a "throwaway" blockchain wallet, get the BTC then send it over to an exchange then delete all the info from the blockchain wallet, it usually only has anything in it for a few hours. It also seems that the wallet IDs that are generated are random or use a complex algorithm so it seems to be hard for someone to brute force the wallet AND the password. Even if they get in it will be pretty much useless as there is no information or btc in there.
This way I don't need a new address every time I "withdraw" the btc and I can keep track of how much I've mined.
It seems that this time that I imported the address to a wallet that SHOULD have been secure and was one that I've set up to "use" for btc-btc transactions. I imported the brain wallet, moved the btc from the previous mining then forgot to delete the public/private key from it.
I did not realize this until it was too late, I don't know how someone even got the blockchain wallet id and figured out my password. I would think that blockchain would also have some sort of protection from someone brute forcing the password. I would think that my other wallets may be compromised if someone hacked my computer... There is a leak somewhere and at this point it looks like blockchain but maybe the private key was compromised and they just imported it into their account and moved the funds. I'm not sure if you can see that in the transaction log.
I did not have that wallet synced to my phone or anything else, I didn't use 2 factor authentication which was something I should have done. It's just that that account was not suppose to have that much funds just sitting there anyway as I usually delete any brain wallet private keys that I may have imported into ANY web wallet.
So, it really sucks and I still have no idea how someone got in the Blockchain.info account or figured out my brain wallet, it was a good long phrase with special characters too.
It seems like my other wallets are safe so far but I'm going to re-secure everything. I really just have no idea how this could have happened... is there some way for someone to figure out what someone's Blockchain's generated wallet address?
I've opened a ticket with blockchain and see what they say, hopefully something can be done but I doubt it...
Thanks to everyone for the suggestions and information, hopefully at the very least we can lock up those coins so no one will want to use them if they are "marked" stolen on every address that the thief sends them to.