You are read more about encryption here, but within the MRC program, no credentials, nor any of the other session negotiation information is sent over in Clear Text. It's all encrypted. You also have additional options of encrypting general data, graphics, and file transfers. Click on the Settings button for your Host Entry, then select the Encryption Options Tab.
Additionally, beginning with version 4.4 and above, we have also added extensive enhancements with regard to the encryption algorithms used within the MRC program. This includes the "Encrypted Windows Logon" authentication method, as well as all features on the Encryptions Options Tab and any other features within the software that requires any type of encryption:
Essentially, for any type of encryption within our software, we are now using Microsoft's cryptographic services providers (CSPs) & CryptoAPIs.