Microsoft released an emergency software update on Wednesday, 12/17/08, to fix a dangerous security hole in its Internet Explorer browser.  The security hole allows compromised web sites to be used to install malicious software.  This critical flaw is present in Internet Explorer version 5 through Internet Explorer 8 Beta 2.

Usually Microsoft issues patches on the second Tuesday of each month, but signs that hackers were taking advantage of this unpatched flaw were evident after December's Patch Tuesday. Hackers have begun using Wednesday as the day to introduce the malicious software, as it gives them the longest lead time until Microsoft gets around to fixing holes on the next second Tuesday.

If you are running Internet Explorer, be sure your Automatic Updates is set to get the Microsoft Updates automatically.  If not, you can visit Microsoft here to get all critical updates:

http://update.microsoft.com/microsoftupdate/v6/default.aspx?ln=en-us

If you have trouble updating your Internet Explorer, you can try Firefox, which is another browser.

Once downloaded, you can choose to use either browser at any time.  Firefox is free to download and you can get it here: 

http://www.mozilla.com/en-US/firefox/ 

After downloading, you would just go to Start>All Programs>Mozilla Firefox, and open Firefox surf the web as you usually do.

You can read about the Emergency Security Patch from Microsoft here:

http://voices.washingtonpost.com/securityfix/2008/12/microfot_emergency_patch_for_i.html

http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9123612

http://computerworld.com/action/article.do?command=viewArticleBasic&taxonomyName=security&articleId=331568&taxonomyId=17&intsrc=kc_top

http://blog.trendmicro.com/ie-zero-day-follow-up-now-featuring-mass-sql-injections/

http://blogs.technet.com/mmpc/archive/2008/12/13/the-new-ie-exploits-for-advisory-961051-now-hosted-on-pornography-sites.aspx