using multiple Firefox profiles to increase security

Question

I am wondering whether it would increase security in any significant way, if I would use two separate Firefox profiles, one for normal browsing and the other for private/secure websites, such as my e-banking.

In case the normal profile got "compromised/infected/malwarized" in any way, would my other profile still be unaffected?

Or what about using two different browsers (on the same system, under the same user)? Would one browser be safe, even if the other was compromised ?

AFAIK, most of the bad things that could happen to my browser only affect the browser itself, i.e. attacker could steal browsing history, bookmarks, or potentially install malicious addon.

Can browser malware also reach outside the browser, i.e. execute shell or programs on the system, such as rm ~ ?

Any ideas would be appreciated

Answer 1

Yes it would increase security, as (malicious) cross-domain information leaks aren't possible between browser instances. You can also minimise the use of plug-ins and add-ons in high security browser environments, as they expose additional attackable surface.

Another way to mitigate the risk of malicious code running in your browser are ad blockers and NoScript-like add-ons. Chrome/Chromium allows you to disable script and plugin execution through its built-in domain-specific policy settings.

Separate browser instances will not protect against malware running on your computer. If an attacker successfully exploits a remote code execution vulnerability in one instance or gets you to run his code through social engineering, the resulting malware has access to all browser profiles/instances under the same user account (unless the malware manages to escalate its privileges).