Microsoft Corporation (NASDAQ:MSFT)’s Internet Explorer users in Australia, Britain and the United States have been warned not to use the browser until a bug problem which appeared over the weekend is fixed. The bug could be exploited by hackers to launch attacks.

Microsoft IE

Users advised to use an alternative browser

The Department of Homeland Security’s U.S. Computer Emergency Readiness Team cautioned that the vulnerability could lead to “the complete compromise” of an affected system. Users in Australia were warned by the government’s Stay Smart Online alert services, which suggested that they could use two short-term fixes from Microsoft Corporation (NASDAQ:MSFT), but it would be better to download and install a different browser, such as Google Chrome or Mozilla Firefox. In Britain also, the U.K. National Computer Emergency Response Team advised people to download an alternative browser and ensure that the browser is the latest version and also update it on a regular basis.

“An attacker who successfully exploited this vulnerability could take complete control of an affected system,” Microsoft Corporation (NASDAQ:MSFT) said in a security advisory. The company also mentioned that the attacker could install programs, view, change, or delete data, or create new accounts with full user rights.

Security of Microsoft XP users remains a concern

The bug which surfaced last weekend is the first serious threat since Microsoft Corporation (NASDAQ:MSFT) stopped security updates for Windows XP. Personal computers powered by Windows XP will remain unprotected even though the company is releasing updates to fix the issue. Microsoft Corporation (NASDAQ:MSFT) IE versions 6 through 11 will face a potential threat until the software giant comes up with a permanent solution. Those versions are the most preferred for desktop browsing, capturing around 55% of global market share, according to research firm NetMarketShare.

Bogdan Botezatu, a senior analyst at security firm Bitdefender, said that this is the first major flaw in Internet Explorer that will remain unresolved for Windows XP users. The bug will continue to disturb users of the old operating system unless they either upgrade to a newer version of Windows which still receives support and thus will receive the bug fix when it is ready. They can also switch to a different browser.

Botezatu has suggested that users not use Internet Explorer on Windows XP in the future and that they instead use an alternative web browser. Security experts have long been advising users to install Windows 7 or 8 before Microsoft Corporation (NASDAQ:MSFT) closed its support for Windows XP.