As of the time of writing of this article, users of the ubiquitous Internet Explorer browser made by Microsoft may be vulnerable to their computers being hijacked due to a serious security flaw in the program that has yet to be fixed.

The security hole would allow malicious attackers to take control of victims’ computers simply by tricking them into visiting a specially-designed website with malicious code. Some 10,000 sites have been compromised since last week to take advantage of the Internet Explorer flaw, says antivirus maker Trend Micro Inc.

These sites are for the most part Chinese ones which have been offering programs that steal computer game passwords to be later sold for money on the black market. The vulnerability however has the worrisome potential to be exploited by ''more financially motivated criminals'' and cause serious damage, worriedly remarks Trend Micro security researcher Paul Ferguson on Monday.

The current flaw is a “Zero-day” vulnerability. That is, it is a flaw that hasn’t been repaired by the software maker, Microsoft in this case. As such, it’s a gold mine for cyber-criminals as victims are defenseless.

Now when the targeted software is the default browser for the large majority of the world’s computers, we have a serious problem. Microsoft says it has so far only detected the vulnerability in Internet Explorer Version 7, which is the most widely used, but Redmond has warned that other versions could be affected as well.

The company is investigating the vulnerability and is considering releasing an emergency software patch outside of its monthly update routine (patch Tuesday), but has made no further comment. Their only solution so far is a series of complex workarounds that reduce the threat.

Meanwhile security experts recommend simply using another browser until the patch is released. Our question is – once you do, why would you want to go back?