You might try a forum called www.bleepingcomputer.com. I have been using them for years to resolve problems with my computers, viruses, malware, slow speeds - just about everything. One of the programs they have you download is malwarebytes.com and I have used it successfully many times.

It is free, requires you to download the programs and do everything yourself, but the advice is spot on. I have been a member of the forum maybe more than ten years.