Legitimate Adobe software receives updates to close security loopholes. Portable versions are frozen in time, leaving your computer vulnerable to exploits. How to Legally Access Adobe Fireworks CS6
Portable versions are often "repackaged" by unknown third parties. These files are notorious for hiding trojans, keyloggers, and ransomware that can compromise your entire system. adobe fireworks cs6 portable download link
If you have an active Creative Cloud "All Apps" subscription, you can sometimes find Fireworks CS6 listed under the "Other Versions" section in the Creative Cloud Desktop app (though availability depends on your OS compatibility). Legitimate Adobe software receives updates to close security