Getting same problem. Installed malwarebytes 3 days ago to investigate a about:blank spyware. Upon reboot malwarebytes detects a trojan.chifrax in c:\windows\temp\setup.exe on startup of PC and deletes it. Interestingly enough, when I reboot and quickly go to Explorer, the setup.exe is there and it's deleted (presumably by malwarebytes), so, it does exist. I suppose I should try and copy it and then check it with another spyware/adware program to see if it's really a problem, or it's a false positive and setup.exe is being created by something else on startup. I'm suspicious that it's indeed the trojan since I still have the about:blank and have not solved this problem yet, so something is playing havoc with my PC