RejZoR
10
This thing should help:
http://users.volja.net/razor256/downloads/AntiRPC_Batch.zip
This little batch script was used for MSBlast and i think it should work for Sasser too. Its so small that you can easily download it in second.
After you see count down timer,simply execute it and it should terminate that timer. After that get yourself a patch for this vulnerability.