sh8.1 Malware?

I have all of my Windows XP Pro Home PC's with all web browsers forced to Sandbox, DropRights and Internet Access plus Start/Run Restrictions.

My wife closed the web browser and left the computer in fear while I was gone this evening. She was on the same 'video on demand' website that she always visits. When I returned home, I found the Sandboxie message that it had not allowed sh8.1 to execute. I searched for sh8.1 on the web and found no clear indication of sh8.1 being Malware. In your opinion, do you think that sh8.1 was Malware?

I did quick scans with both Malwarebytes Anti-Malware and Emsisoft Emergency Kit and nothing was detected. I assume that Sandboxie trapped and killed any Malware.

Thanks in Advance.