Prevx1 is far behind other HIPS in a HIPS test

Well, that malware would have to bypass the browser, the AV and the behaviour blocker in non-sandboxed surfing sessions(very rare). Not counting that I have to allow a lot of things like a stupid. Finally, the firewall would prevent almost all kinds of data leak

 

It looks like it is very hard to bypass since it needs to bypass one by one. However sometimes it is not true. For example, if a malware writer can find holes in your OS which can install rootkits, it can effectively bypass all secuirty applications.

AV -- simply create variants, or better a bespoke malware. Test AVs before sending out your malware. It can effectively bypass all AVs. The underground will provide virtools to facilitate the creation.
Firewall -- fool you into pressing "allow" (the content of the popup will look legitimate), or simply bypass it (various leakge technique)
Behaviour blocker -- again fool you into pressing "allow" (the content of the popup will look legitimate), or simply bypass it

How effectively is it when all security apps combine together? No idea since there's no test about it. But I won't say it is rare. It is just not too easy. I have read too much on how powerful the bad guy can compromise our protection. For example, even the well-protected servers of the famous websites have once been hacked by the bad guys.