(1) Software designed to steal personal information or perform some other illegal operation. It is malicious software that causes a crime to be committed. See warez and malware.

(2) Software that helps someone perform an unwanted or illegal act via the computer. Programs and documentation that enable less technical people to set up their own spam, virus or phishing attacks are crimeware, essentially a software development kit for scoundrels. The good news is that the documentation is probably as horrid as that of most popular commercial software.