This is arguably the most immediate danger. Cracked software is a primary vector for malware distribution. When you download a "portable" version from an unofficial source like Mega, you are downloading an executable file that has been tampered with.
What of DraftSight are you trying to configure? draftsight portable mega extra quality
An "extra quality" build is streamlined to strip out unnecessary background telemetry, auto-update daemons, and startup services. This reduction in overhead frees up CPU and RAM. The software runs faster and smoother, even on modest laptops. Best Practices for Using Portable CAD Software This is arguably the most immediate danger
I understand you're looking for information on with an emphasis on "Mega" and "Extra Quality." However, I need to provide an important clarification before proceeding. What of DraftSight are you trying to configure
Dassault offers a legitimate free version for personal and educational use. It requires installation, but it is 100% safe, has full .dwg support, and gets updates. It just isn't portable.