Update: The first of May Microsoft released a fix for the vulnerability, also for Windows XP. It is also possible to protect your machine by upgrading to the latest version of Adobe Flash player according to sources on the Internet.
Yesterday we got word from Microsoft that there is a security hole in Internet Explorer versions 6 through to 11 and there is still no fix to this issue. The sad thing about this issue is that it is actively being exploited and that means, if you are using IE now you are at risk.
Microsoft Security Advisory 2963983
What is the risk? An attacker could install software to your computer, this software could be used for anything (stealing your information, attacking other services on the Internet or other). You would not know that it would happen even, you would just be browsing along and it would happen silently.
What can you do? Use another browser is the simple answer. Microsoft is going to patch this in a week or two (next patch Tuesday the 14th of May is good bet) but remember, if you are on Windows XP it might not even get a patch since it is out of support. My suggestion is simply try another browser, some good suggestions are:
If you never turn back to IE, then you do like most of us. Should you really miss IE just wait until mid-may and you will be fine again. If you really need to use IE there are some quick fixes you could do, one is to disable flash, another is to install Enhanced Mitigation Experience Toolkit version 4.1. You can find more information about that by clicking on the the Microsoft link above.
Sources: http://thehackernews.com/2014/04/new-zero-day-vulnerability-cve-2014.html, http://www.symantec.com/connect/blogs/zero-day-internet-vulnerability-let-loose-wild
