The FBI has said numerous times that the greatest threat to personal PCs is java script. It is the number one way hackers employ their malware. NoScript has been around for almost a decade and it is very easy to control it's functions. I am an expert in security add-ons for firefox and I run 15 security add-ons on my Waterfox browser and have since before Firefox was even called Firefox. I highly recommend RequestPolicy to work side by side with NoScript. It works pretty much the same way so if you are comfortable with NoScript's options then you will also be able run RequestPolicy as well.
I also recommend Ghostery, Better Privacy, HTTPS Everywhere and add block plus for starters. Everything else I run is for advanced users only but my complete list is;
ad block plus
ad blocker for gmail
better privacy
certificate patrol
cipher fox
cookie controller
dnssec validator
dr web anti virus link checker
ghostery
https finder
https everywhere
no script
perspectives
requestpolicy
wot
lastpass
Why do I use all of these programs. Simple; Viruses are now spread through Facebook advertisemants where they steal your identity with your approval. Just by using Facebook you are agreeing to allow other advertising companies to take your personal information and create accounts without your knowledge. Advertising is run through JAVA script and it is very difficult for Anti Virus to detect those security breaches. The malware is hidden in 3rd party apps that are included with your downloads and are also called PUPS (potentially unwanted programs) Today they are able to hide key loggers and advertising programs that highjack your browsers. They hide deep within the registry unable to be detected by registry scanners like CCleaner and other easy to use cleaners. They also act like worms hiding in other well hidden folders. You need to do a deep cleaners that takes hours of work just to remove modern day PUPS that even Malwarebytes will not detect.
That's why.
If you are or have been infected with PUPS, if your anti virus or even Malwarebytes have detected and removed PUPS from your PC it is VERY likely that there are still some hidden in your OS. Don't take PUPS lightly. It is one of the most common ways that malware infects your OS. If you PM me I will send you Step by Step instructions on how to permanently remove them.