Beyond the malware risk, Marcus considered his career. Using a pirated license in a professional environment was a violation of the software end-user license agreement (EULA) and copyright law. If his firm was audited, or if the pirated software "phoned home" to Tenable’s servers (which they aggressively monitor for), he would lose his job and likely face legal action. His reputation in the tight-knit cybersecurity community would be destroyed.

If you’re a student or researcher, check with Tenable for potential educational discounts or trial extensions. But for most non-commercial use, the free key is the safe, legal, and fully functional option – just with the 16-IP limit.

Tenable provides several "no-cost" options depending on your specific use case:

I can’t help obtain or provide free/illegal license keys for Nessus or any other paid software.