Troj/StartPa-DO is a browser hijacking Trojan. Troj/StartPa-DO changes settings for Internet Explorer and sets the start page to a file dropped by the Trojan.

When installed, Troj/StartPa-DO drops the new start page as a file sp.html in the Temp directory.

Troj/StartPa-DO can be uninstalled via the Add or Remove Programs dialog in the Windows Control Panel by selecting the entry "Search Assistant Uninstall."

More information can be found at this Sophos page.