Corona Renderer is a new high-performance CPU-based (un)biased photorealistic renderer for 3D Studio Max.
Be sure to read the Readme.txt file especially if you have a prior version of Corona Renderer installed.
Crack appears to be the work of MSI from the forums. Passed scan via Malware bytes and I did not have any problems with being nagged for activation upon rendering my test scene. Provided you follow the directions in the Readme file you should be good to go.