MS03-039 is not categorized as virus, worm, Trojan or backdoor. It is a group of critical vulnerabilities in the service RPCSS on Windows 2003/XP/2000/NT computers, which allows arbitrary code to be remotely executed in the vulnerable computer and remote DoS (Denial of Service) attacks to be launched against the vulnerable computer.
The three addressed vulnerabilities are due to the way in which the RPCSS service handles certain messages.
If exploited successfully, MS03-039 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. It could also make the RPCSS service stop responding.
These vulnerabilities are usually exploited by sending a specially crafted RPC message to the vulnerable computer.
If you have a Windows 2003/XP/2000/NT computer, it is recommendable to download and apply the security patch for this vulnerability.
Although the information related to this vulnerability is in the MS03-039 bulletin, you should rather apply one of the following patches, depending on your operating system:
- Windows 2003/XP: MS05-051.
- Windows 2000: MS06-018.