Compromised installation packages are one of the most common vectors for deploying Trojan horses, spyware, and ransomware. A "patch" or "crack" requires administrative privileges to run, giving malicious code full access to your operating system.
For a Windows PC, Adobe Premiere Pro CS5.5 required a 64-bit edition of Windows Vista or Windows 7. The minimum processor was an Intel Core 2 Duo or AMD Phenom II, with at least 2GB of RAM (4GB or more recommended). Installation required around 24.3GB of free hard-disk space.