MS05-039 is not categorized as virus, worm, Trojan or backdoor. It is a critical vulnerability in Plug and Play (PnP) in Windows 2003/XP/2000, which allows arbitrary code to be remotely executed in the vulnerable computer or local elevation of privilege.
If exploited successfully, MS05-039 allows hackers to gain remote control of the affected computer with the same privileges as the logged on user. If this user had administrator rights, the hacker could take complete control of the system: create, modify or delete files, install programs, create new user accounts, etc.
Depending on the operating system under attack, several requirements must be fulfilled to compromise the computer:
- On Windows 2000, any user can remotely exploit the vulnerability by sending an specially crafted packet.
- On Windows XP Service Pack 1, the vulnerability can also be remotely exploited, but such packet must be sent by an authenticated user.
- On Windows XP Service Pack 2 and Windows 2003 Server, it is necessary that the user runs a specially crafted application in order to obtain local elevation of privilege.
Attacks can be launched across the Internet, but a firewall could be used in order to prevent those attacks.
If you have a Windows 2003/XP/2000 computer, it is recommendable to download and apply the security patch for this vulnerability. Click here to access the web page for downloading the patch.
Later, on October 11, 2005 this patch for the Plug and Play vulnerability was revised and replaced by an updated patch, whose bulletin number was MS05-047.