It doesn't matter if you patch well-known vulnerabilities if the Chinese are using undocumented flaws in browsers to attack you. HN doesn't want to hear this, but in the worst case IE is probably tied with Firefox as the most secure browser.
The difference being that
Once the malware is downloaded and installed, it opens a back door that allows the attacker to perform reconnaissance and gain complete control over the compromised system.
is less feasible in Firefox than it is in IE. Firefox forces you to download an executable and then manually run it, so a user would be conscious that he or she is installing a program. It is still possible (last I knew) in IE to install a program practically in the background, or to get broader OS control through a browser vulnerability.
Unfortunately not. I already encountered malware specifically targeted to Firefox that was fully automatic.
It used some Mozilla specific JS hooks to launch Acrobat plugin. This in turn loaded tiny infected PDF that exploited some Acrobat security hole which allowed to directly execute code on your machine.
It was enough to visit a compromised website, no further user action required. All was happening automatically, practically invisible to the user. I only noticed it because Acrobat plugin is a massive resource hog, so I managed to kill it in time before it could execute a payload.
Acrobat plugin opens automatically if you embed a pdf.
It was actually quite sophisticated malware - heavily obfuscated, assembling itself from pieces spread all around the world, jumping through several hoops of compromised servers.
When I finally managed to reverse engineer to JS code that carried the infection, it was full of functions I didn't even know existed. Not usual JS, more like API hooks to the underlying platform, with special prefixed names. These names indicated it was about plugins.
BTW it was multiplatform, attacking not just Firefox, there was a browser detection and browser specific code paths for several popular browser. I remember there was also something trying to use Silverlight.
Oh, and it was multipurpose. Besides trying to infect your PC with a malware, it was also earning money. Some parts of JS were loading ads in invisible frames, presumably to be part of some distributed click farm.
Has IE ramped up security in later versions, has it always been like this or what?
Meaning both are more secure than Chrome? What about the process sandboxing Chrome does?
Finding it very useful!
Maybe a reliable IE clientside bumps the number up north of $200,000, because folk wisdom puts the actual value of a reliable IE in the six figures. I don't know. I know what a year of time from someone who can find these bugs costs.