If you constantly use your internet browser (especially Chrome), you will probably notice that the more tabs you open, the slower your machine gets. Each open tab consumes resources from your processor.
There are ways to pause unused tabs, such as The Great Suspender, but these are extensions that can cause other issues, even at the security level.
This being the case, the slowdown which we talk about in this article is of another order, much more insidious. Without even having to install malicious software on your machine, hackers can now run a script via a simple banner ad to take advantage of the simultaneous computing power of hundreds of thousands or even millions of computers. This enables them, for example, to generate cryptocurrency units or launch a DDoS attack by creating a dematerialized supercomputer with the stolen capacity from all hacked browsers.
As this hacker points out, the use of WebAssembly would be even more efficient and even more destructive because it is faster in terms of execution. Hackers might not limit themselves to redirecting banner ads. WordPress plugins or other elements which are part of the architecture of a website could also allow the execution of malicious scripts.
This kind of intrusion is totally unnoticed by conventional anti-virus. The best way to protect yourself is to choose a browser (such as URbrowser) whose security settings you control, especially via the adblocking function.
Forewarned is forearmed.