In software dealing with security, randomness is often necessary to generate keys or tokens for resetting passwords or identifying sessions. There, randomness is required to be unpredictable for an attacker. However, sometimes developers do not use cryptographically secure pseudo random number generators (CSPRNG) in this scenario. Instead they utilize faster pseudorandom number generators (PRNG). Consequently, the question arises how hard it is to attack a common (not cryptographically secure) random number generator.