Optitex 12 or 13 (released 2010–2015) can sometimes be found on archive.org or through second-hand license transfers. Legally, you can buy a used license from a company that upgraded, then transfer it via Optitex’s license transfer form. This is legal and often cheap ($200–500).
Security researchers consistently find that 78% of “keygen” and “cracked CAD” downloads contain hidden malware. Common payloads include: optitex 21 free download link