Security specialist eEye Digital Security has discovered two high risk security holes in Microsoft's Outlook and Internet Explorer software.

The flaws allow malicious code to be executed on both programs with minimal user interaction, according to the eEye security bulletin. Hackers could gain complete control of users computer systems.

It is thought all versions of Windows XP, NT and 2000 are vulnerable to the attack.

Ben Nagy, a security engineer at eEye said, "At this time, Microsoft is not aware of any malicious attacks attempting to exploit the reported vulnerabilities, and there is no customer impact based on this issue. Depending on the severity of the flaw, Microsoft will issue a fix through a service pack, one of the company's monthly patches or and out-of-cycle security update."