The only way and is the only way that a computer can get infected by a virus is to download the virus and execute the code. Downloading is not enough you must execute it!
For example, if you receive an email with a virus attachment and execute the attachment you get infected.
This is common to all browsers, but here is the big difference between them:
With IE/Outlook if you click on attachedvirus.exe it executes and install the virus.
With other browsers clicking on attachedvirus.exe opens dialog box for "save as" the attachedvirus.exe in some folder.
So you must save the virus first and you must execute the saved file to be infected. This is a two pass routine that eliminate any possible infection by an accidental clicking.

Part II
Again, the only way to get infected is to download a virus and execute it.
Microsoft has created the ways and opened the gates of hell for IE downloading a file and authomaticaly execute it without your knowledge, so going to a malicious site or Microsoft "secure" site that is hacked, you got infected by virus. Virus are not very common in sites, but any kind of spies, popups installers, browser redirectors, etc are very common and incentived by Micro$oft and partners as compulsory propaganda in your computer. The goal is for every five minutes that you are working on something in your computer, opens a windows with some advertising selling you something! Buy, Buy, Buy, Buy!
With browsers like Mozilla/Firefox/Netscape this is not possible.

Message edited on: 04/04/2005 12:58

Stupidity also evolves!