SONAR.Heuristic.120 is a heuristic detection for processes based on certain attributes.
Files that are detected as SONAR.Heuristic may be malicious. We suggest that you submit any such files to Symantec Security Response. For instructions on how to do this using Scan and Deliver, read Submit Virus Samples
Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":