Because MISource writes progress files to your hard drive, some virus protection programs may view this action as "malicious". If you see a warning from your virus protection program, allow MISource to run the scripts.
In the example below (Norton Anti-Virus 2002), you would select Authorize this script, to allow the TILA (Triad Interactive Learning Architecture) program to delete the temporary progress file. TILA is the program that runs MISource.