What's Operating system: Windows 7 SP20?
Real-time protection
Are you using a trial for VIPRE and MBAM or did you bought them?
Because you are an Advance user a highly recommend that you try the VIPRE HIPS, this should give you even higher degree of protection.
Virtualization:
You should give Sandboxie try, really useful when opening to unknown/suspicious apps or going to shady sites (not that you should do that ..but it happens

)
Watch the below video with Sandboxie at work :
Sandboxie (Free/Paid) -
link
Sandboxie runs your programs in an isolated space which prevents them from making permanent changes to other programs and data in your computer.
Additional on-demand scanner:
Hitman Pro (Trial) -
link
An on-demand scanner using multiple anti-malware engines and cloud technology. It offers unlimited free scanning but once you use it to remove detected malware it switches to a 30-day trial version. I recommend using it after you've scanned your hard-drive with the other products you have installed.
Additional browser protection:
Are you using any addons for Firefox if not you can try the bellow plugins:
WOT (Free) -
link
To help you avoid malicious sites you can use Web of Trust (WOT) a website rating browser plugin. After you add it to your browser make sure you only visit websites rated "Green" by WOT
VTzilla (Free) -
link
VTzilla is a Mozilla Firefox browser plugin that simplifies the process of scanning Internet resources with VirusTotal. It allows you to download files directly with VirusTotal's web application prior to storing them in your PC. Moreover, it will not only scan files, but also URLs.
The scanning options are embedded in Firefox's context menu and download dialog, making the analysis process as easy as clicking a single button.
Adblock Plus (Free) -
link
Adblock is a content-filtering extension for Mozilla Firefox- and Mozilla Application Suite-based web browsers. Adblock allows users to prevent page elements, such as advertisements, from being downloaded and displayed.
LastPass (Free) -
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LastPass is an online password manager and form filler that makes web browsing easier and more secure.
PS: Welcome aboard!