I don't think it is so much a problem with Firefox, as it is the
operating system that it is running on. I don't use my Windows XP
virtual machine for browsing. I do all my browsing in Linux. According
to
www.stopbadware.org
there are now over 38000 websites that spread windows spyware, malware,
and viruses. The operative word here is windows. Some of these sites
were hacked by crime syndicates. It is best to use Google for your
searches, since they now warn you, if a site is on the badware list.
Vista is supposed to be more secure, but in the end it is still Windows,
built on a flawed security model with add-on security modules. Other
operating systems are intrinsically secure by design. It has nothing to
do with the popularity of an operating system. So whether you are using
Firefox or IE 7.0 on Windows, you are just riding in different seats in a
train that is careening off of a cliff.