MS05-043 is not categorized as virus, worm, Trojan or backdoor. It is a critical vulnerability in the Print Spooler service in Windows 2003/XP/2000, which allows arbitrary code to be remotely executed in the vulnerable computer.
If exploited successfully, MS05-043 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 remotely:
- On Windows 2000 and Windows XP Service Pack 1, any user can exploit the vulnerability by sending an specially crafted packet.
- On Windows XP Service Pack 2 and Windows 2003 Server, the vulnerability can also be exploited, but such packet must be sent by an authenticated user.
However, any user that can locally access computers with any of the vulnerable operating systems and run a specially crafted application can compromise such systems.
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.