If your goal is simply to perform GIS tasks without cost—rather than specifically using MapInfo—you have excellent free options that are legal, safe, and often more powerful.
If you truly need MapInfo Professional, here are the legal and safe pathways: Mapinfo Professional 12.5 Free Download
If your legacy MapBasic application or hardware dongle system requires specific version 12.5 (and not newer), follow these steps: If your goal is simply to perform GIS