Recently I got infected with smartinf.ru browser hijacker. I made a full scan with my Avast Internet Security 2015 with all options on ( test all files and even detect PUP), but Avast failed to detect anything. As a result I had to manually track every file of the malware and clean the registry which took me about an hour to do so. This is not a complaint topic just a little feedback. Please guys i paid for my product and would like it to prevent or detect such hijackers. Thank you for your time and have a nice day 
did you try a scan with Malwarebytes?
there may be leftover files to remove so i recomend …
Instructions https://forum.avast.com/index.php?topic=53253.0
Attach Malwarebytes and Farbar Recovery Scan Tool logs … 3 logs total
See below the box you write in … Attachments and other options
when done a malware expert will assist you