(1) A person who breaks into a computer system without authorization, whose purpose is to do damage (destroy files, steal credit card numbers, plant viruses, etc.). Because a cracker uses low-level hacker skills to do cracking, the terms "cracker" and "hacker" have become synonymous with the latter becoming the most widely used term. See hacker, ECPA, CFA and virus.

(2) A person who reverse engineers software and modifies it for fun. Often applies to game software. See disassembler.