|Browser hijacks are fairly common malware tactics. Spybot S&D is useless to the point I've seen government IT departments stop using it less than a week after purchase.|
My recommendation is this:
1. run Bleepingcomputers Combofix from SAFE MODE as an administrator. (This takes forever)
2. Run Malwarebytes Anti-malware from SAFE MODE as an administrator (Update before running a FULL scan)
Malwarebytes should catch the overt malware, while Combofix tends to catch and fix the much more sneeky stuff like rootkits that allow backdoor hidden installations that can bypass and/or shut down antivirus software.
the reason to run them from safe mode is because windows will only load up the basic drivers required to run, which makes it more likely that malicious programs will be found and removed.