Most "cracks" are actually Trojans in disguise. You might get the software for free, but you’ll pay for it with stolen data.
If you have a legitimate key but version 4.1.26 won't accept it, check the following: gridinsoft antimalware 4126 license key
Version 4.1.26 was a significant update that improved the scanning engine speed and optimized the memory usage, making it a popular version for users with older hardware. The Risks of "Free" License Keys and Cracks Most "cracks" are actually Trojans in disguise