noun
pirated software; software piracy
Refers to unauthorized copies of software, or the act of distributing/using them. Common in computing contexts.
海賊版ソフトウェアの使用は法律違反です。
Using pirated software is against the law.
彼は海賊版ソフトウェアをダウンロードしてしまった。
He ended up downloading pirated software.
違法コピー means 'illegal copy' and is a more general term, not limited to software.
Compound of 海賊版 (pirated edition) + ソフトウェア (software).