Many information security systems rely on cryptographic schemes that need truly random numbers be secure. In recent months there have been several high profile news stories about weaknesses or potential compromises in both software and hardware random number generators. A compromised random number generator is difficult to catch because it can output random looking data that is predictable to an attacker only. In this talk I describe how to go from knowledge of a weakness in a random number generator to a full security compromise. We will look at examples including how to fully decrypt a TLS stream, how to compromise a bitcoin wallet by looking at the ECDSA signatures on the public block chain, how to factor improperly generated RSA keys, and more. There will be live demos and discussions of interesting ways to pull off these attacks.