I Would download a program called
Superantispyware and run it it is free and will take it out .
It is mostly installed by 3rd party software like when you download a free app and it includes other software you have to opt out of .

Malwarebytes you have used and it works well
Also grab Hijack this its a great program for getting rid of minor things like this

Ive taken this crap out of many of my clients computers with just these 2 programs and

Also Avast is not very good i have allot of clients that come in and they have avast on there computer and there infected and did run Avast and found nothing .

i remove this and install AVG Free . i know people dont care for it , but imo it works better then Avast .

i have these 3 on my computer and im not infected , dont remember the last time i was infected tbh .

Hope this Helps