MS10-047 is not categorized as virus, worm, Trojan or backdoor. It is a group of important vulnerabilities in the Windows Kernel on Windows 2008/Vista/XP computers, which allows to gain local privilege escalation and to launch denial of service attacks.
The kernel is the core of the operating system and provides basic services for all other parts of the operating system.
If exploited successfully, MS10-047 allows to gain unauthorized privileges on a computer or network. An example of privilege elevation would be an unprivileged user who could manage to be added to the Administrator's group. In such case, the hacker could take complete control of the system: create, modify or delete files, install programs, create new user accounts, etc. It could also cause the system to stop responding until it is restarted.
MS10-047 is usually exploited by running a specially crafted program in the vulnerable computer. In order to do so, a hacker must be able to log on locally to the system.
If you have a Windows 2008/Vista/XP computer, it is recommended to download and apply the security patch for this vulnerability. Click here to access the web page for downloading the patch.
Bear in mind that this security patch replaces a previous one, called MS10-021.