It may be the most common and used internet browser out there, but as far as security goes, Internet Explorer is flawed. Period.
A security flaw in Internet Explorer (versions 5 and up) poses a serious threat as it enables hackers to hijack the users' passwords. Even though the most sensible thing to do is to switch to a different browser (temporarily or permanently), the head of Microsoft UK's Windows group, John Curran, says that, "I cannot recommend people switch due to this one flaw."
Wrong! Switch to a different browser as soon as possible, seriously. FireFox is a fast, excellent, customizable browser-it has spell checker too! Other decent alternatives are Safari and Opera.