Fact Check

F1 Key Virus

Can a form of malware can be activated by prompting Internet Explorer users to press the F1 key?

Published Mar 4, 2010


Claim:   A form of malware can be activated by prompting Internet Explorer users to press the F1 key.


Example:   [Collected via e-mail, March 2010]

Microsoft has issued a warning against a new virus that they do not yet have a patch for ... it is attached to Internet Explorer and the user will get a window prompt requesting them to press the F1 key. Doing this then causes malicious code to be run on your computer.

So ... DO NOT press F1 if you are prompted - no matter how many times. Evidently, it will pester you repeatedly. Either X out of the window or Explorer all together.

Thanks for your diligence in keeping these viruses to a minimum.


Origins:   As noted in a 1 March 2010 Microsoft Security Advisory, a vulnerability in VBScript opened the door to a potential Windows-based exploit tied to luring users of Microsoft's Internet Explorer web browser software into pressing the F1 key:

Microsoft is investigating new public reports of a vulnerability in VBScript that is exposed on supported versions of Microsoft Windows 2000, Windows XP, and Windows Server 2003 through the use of Internet Explorer. Our investigation has shown that the vulnerability cannot be exploited on Windows 7, Windows Server 2008 R2, Windows Vista, or Windows Server 2008. The main impact of the vulnerability is remote code execution. We are not aware of attacks that try to use the reported vulnerabilities or of customer impact at this time.

The vulnerability exists in the way that VBScript interacts with Windows Help files when using Internet Explorer. If a malicious Web site displayed a specially crafted dialog box and a user pressed the F1 key, arbitrary code could be executed in the security context of the currently logged-on user. On systems running Windows Server 2003, Internet Explorer Enhanced Security Configuration is enabled by default, which helps to mitigate against this issue.

However, this vulnerability was addressed in an April 2010 Microsoft security update, so only users of Microsoft Windows 2000, Windows XP, or Windows Server 2003 platforms who do not have automatic updates enabled and who have not manually applied any security updates since April 2010 would still be at risk for the F1 key exploit.

Last updated:   5 July 2010

David Mikkelson founded the site now known as snopes.com back in 1994.