Do not use "cracked" software sites. Instead, use:
Think of early Super Smash Bros. Melee or early patches of League of Legends where certain characters were virtually unstoppable. This created a high-stakes, "anything goes" atmosphere that modern, sterilized competitive scenes sometimes lack.
This is the most significant hazard. Software updates exist primarily to patch security exploits.
Older versions are often sought after because they provide a "no-frills" experience with lower CPU overhead.