The IE vulnerability, which is the third found in a month, could provide the same avenue as the other flaws for installing spyware on a machine.
In a prepared statement, a Microsoft spokesperson said: "Microsoft is working to provide a series of security updates to Internet Explorer in coming weeks that will provide additional protection for our customers.
"The intentional use of exploit code to cause damage is a criminal offence; accordingly, Microsoft continues to work aggressively with law enforcement to help prosecute individuals or organizations who engage in these activities."
If exploited the flaw compromises a Windows ActiveX component called Shell.Application.
The vulnerability is similar to the JS.Scob.Trojan, which appeared last month and attacked IIS servers and spread malware through IE's ActiveX scripting.
Computer student Jelmer Kuperus found the vulnerability.