A VPN is supposed to protect your privacy. If you use a cracked version, the modder who altered the APK could have:

Security is the cornerstone of any reputable VPN. Tornado VPN Pro uses robust encryption standards (often referred to as Military-Grade) to protect data packets. This is particularly vital for users who frequently connect to unsecured public Wi-Fi hotspots in cafes, airports, or hotels. With this encryption, even if a hacker intercepts the connection, the data remains unreadable code.