A permanent repair to the security flaw will be released Friday. Microsoft Corp. began offering a temporary patch for the problem Wednesday on a part of its website set up for technical issues.
The permanent solution to the problem will be automatically installed on PCs running on Microsoft's Windows operating system if the machine is set up to receive important updates. The temporary repair requires clicking on a link.
Microsoft Corp., which is based in Redmond, Wash., is urging PC users who haven't enabled their machines for automatic updates to retrieve and install the permanent patch as soon as possible Friday.
Although Microsoft says "the vast majority" of users have not been bitten by the security bug, the potential for trouble prompted a German government technology agency to advise using other Web browsers besides Internet Explorer.
German watchdog warns of Internet Explorer breach
The browser's "weak point is already being used for targeted attacks," Germany's Federal Office for Information Security warned Tuesday, adding that the code behind the attack is freely available online and therefore might spread rapidly.
"This is not a massive problem. There have been only a small number of targeted attacks," said Microsoft spokesman Thomas Baumgaertner. He could not provide a figure of the number of attacks recorded so far.
In its warning published late Monday, Germany's IT watchdog called on people using Windows XP or Windows 7 operating systems and Internet Explorer versions 7, 8 or 9 to switch to alternative browsers until Microsoft updates the browser's security features.
Attackers lure users to an infected website, for example through an emailed link. Visiting the website then allows hackers to introduce codes to take control of the user's computer, the BSI agency said.
Baumgaertner noted that people should always be vigilant when clicking on links from unknown sources. He also added that many antivirus programs might already be updated to protect their users against attacks through the browser loophole.
Once the dominant Web browser, Internet Explorer has been losing market share in recent years to Google's Chrome, Apple Inc.'s Safari and Mozilla's Firefox.
At least one research firm maintains that Chrome eclipsed Internet Explorer as the world's most popular browser earlier this year. Other measures still rate Internet Explorer as the market leader.
Google Inc., one of Microsoft's fiercest rivals, touts Chrome as a faster and safer alternative to Internet Explorer.
Microsoft, the world's largest software maker, will release a new version of Internet Explorer, along with a dramatic overhaul of Windows, on Oct. 26.