What is the threat from the use of unlicensed software?

Responsibility before the law of the country where the unlicensed software is used. Attackers can also embed malicious programs in such software that run on the target computer and which the standard antivirus may not detect. Unlicensed software can be unfinished (stolen beta version from the developer, trial version, etc.), work incorrectly (hang, because hackers have cracked this software illiterately). It is best to use legal software (without intruding on the source code), but use the “left” serial number if you don’t want to pay.