If you use Internet Explorer 6, 7, 8 or 9 as your default browser on a Windows PC, security experts are advising you to use a different Web browser until Microsoft patches a critical vulnerability in IE. Microsoft on Monday confirmed that hackers were actively exploiting an IE vulnerability that could allow an attacker to take over your PC. The exploit does not affect users running IE10 on the Windows 8 Release Preview.
So far, Microsoft says it has received reports of "a small number of targeted attacks" using this exploit. The software maker is working on a security patch for the problem, but the company has not yet said whether it will issue a security update as soon as possible or as part of its monthly "patch Tuesday" update cycle. The next "patch Tuesday" would be October 9.
The exploit was made public on security firm Rapid7's Metasploit Project and first discovered in the wild by security researcher Eric Romang. Metasploit is advising users to dump IE until Microsoft issues a security update. The new IE security flaw was developed by the same group that created the recent Java zero day flaw, according to Metasploit.
Microsoft's Internet Explorer makes up about 48.75 percent of active Web browsers worldwide, according to Net Market Share.
Microsoft said the exploit makes it possible for a hacker to take advantage of corrupted memory in your system and execute malicious code on your PC. The end result is that, if attacked, a hacker would have the same control over your PC that you do. So if you login as an administrative user, which many Windows users do, then the hacker would be able to do everything you can including install or remove programs; view, change, or delete files; and even create new user accounts with full administrative rights.
How It Could Happen
For most home users, the exploit would require you to visit a malicious Website where the attack could be carried out. The attack is also possible via compromised sites that may have malicious advertisements on them or host user-provided content. The most likely scenario for getting hit with this exploit appears to be phishing attempts where a hacker attempts to trick you into visiting a malicious site.
What Microsoft Advises
While Microsoft is working on a patch for the new IE exploit, the software maker is advising users to employ a multi-step workaround including downloading and installing a security toolkit, and setting your Internet security zone settings via Tools>Internet Options>Security to "High." The company is also advising you to configure Internet Explorer to either disable Active Scripting or prompt you before running any script. You can find out more details from Microsoft's security advisory.
Think About Switching, For Now
Employing this workaround will make it much harder to take advantage of the security threat, but it won't eliminate the problem entirely. That's a lot of hassle to go through just to mitigate but not eliminate a serious security flaw, which is why it might be more advisable to just dump IE until the problem is fixed.