As a dice site owner (SAFEDICE.COM), recently I noticed on my log that there were many failed sign in attempts ( thousand of them ). Those failed attempts were using a username that does not exists on our database. However, there were also many correct attempts, probably around 20% of them.

This is not a brute force attack, since each trial use a different combination of username and password. Not to mention that brute force attack will be rejected by our server. the attacker seems to have a list of username and password, this make it difficult for me to differentiate between an attack and normal login. I have a strong suspicion that the list was acquired from another bitcoin site.

To all of you concerned with the safety of your account, whether its on SafeDice or another site, please always use 2FA and different password for each site.

I have just created a tool for SafeDice users to check if there was suspicious login attempt on their account. You can type /amisafe in the chat room, the server will reply you with the result. For those of you just want to check your username, you can just sign up and check immediately.

Again I strongly encourage everyone in bitcoin community to use 2FA whenever possible, and if there is any other bitcoin site owner has information about this please share this information.