RNAAPP.EXE is a core component to the windows dial up networking.

This would explain why it happens when you dial up.
source
rnaapp - rnaapp.exe - Process Information
Process File: rnaapp or rnaapp.exe
Process Name: Windows Modem Connection
Description: The Windows Modem Connection Process handles dial-up modem connections
Common Errors: N/A
System Process: No
techies guide to combating rnaapp