Because there is no official source, these files are distributed through file-sharing sites, torrent trackers, and dubious "software download" portals. This distribution chain is a primary vector for malware.
If you require a legal, safe, and genuinely portable 64-bit editor from Adobe, you cannot use "Pro." However, syncs via the cloud and can be installed on any machine with your login. While it lacks the advanced color grading and multi-cam features of Pro, it is the only official "portable" workflow Adobe offers.
If you are a professional: