Internet Explorer 9 vs. Firefox 4: Which is Safer?

Over the past few years, I’ve
compared the security of Internet Explorer and Firefox several times. With both
products well into their respective beta cycles, it’s time to revisit the
question: which browser is a better choice for the security of an average user?

This month, I went into my lab and
installed the latest beta version of each browser, and have updated the
comparisons I’ve made in the past. For the record, I tested Firefox 4.0 beta 7
on a Macbook Pro running Apple’s Snow Leopard operating system with all current
patches installed. For Internet Explorer (“IE”), I used IE 9.0.7930.30.16406
(wow!) on Windows 7 Home Edition (32 bit) running in a Parallels version 6
virtual machine with 3.5 GB of RAM.  (I
felt this was fair. After all, I’m comparing security features, not browser
speed…)

The good news is that there truly
is much to like about both browsers. Safe browsing features, privacy guards and
such have never been more robust. The bad news is that, to be secure on today’s
Web, both browsers require some tweaking, as their default confgurations are less
than ideal. Even though I am someone who enjoys tweaking tools, surely that’s
not the case for the average consumer. I fear few users will ever take
advantage of the security features they’re given.

Still, I feel I could use either
Firefox or IE in a reasonably secure way, given some tweaking and fddling time.
In the case of IE, most everything I’d need is built in, which is a good thing.
In the case of Firefox, I’d need a plug-in to feel safe. So let’s dive in and
take a look at the details.

I feel a browser with a huge market
share is not as safe as one with a miniscule market share. This is due simply
to the fact that miscreants generally tend to write their malware to products that
have large market shares. It’s a simple matter of economics in most cases.  Further, it in no way indicates which browser
is more secure only which one is safer because there are fewer attacks affecting
it.

In our case of IE vs. Firefox,
their respective market shares are looking more and more similar. In the past,
IE’s market share was so vastly bigger than Firefox and others that it was
pretty easy to assume a lower profle browser was less likely to be targeted by miscreants.