Audacity is the world’s most popular free audio editor. It supports multitrack recording, noise reduction, spectrogram view, and VST plugins. No serial number. No malware. It runs on Windows, Mac, Linux.
Using a cracked serial number violates copyright law (Digital Millennium Copyright Act in the US, EUCD in Europe). While individual users are rarely sued, commercial studios face fines up to $150,000 per instance of unlicensed software.
Pirated software often introduces artifacts, pops, or clicks into exported audio. Some cracks corrupt save files. Imagine mixing a podcast for 40 hours only to find the project file is permanently damaged.