Trojan.VirtualRoot

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Discovered: August 04, 2001
Updated: February 13, 2007 11:36:41 AM
Also Known As: Codered II, Trojan.Win32.VirtualRoot [KAV], W32/CodeRed.c [McAfee], Troj/Codered-II [Sophos], Win32.CodeRed.C [CA], TROJ_CODERED.C [Trend]
Type: Trojan Horse
Systems Affected: Windows
CVE References: CVE-2000-0663



Trojan.VirtualRoot is a Trojan horse program that is dropped by the CodeRed II and CodeRed.F worms. The Trojan allows a hacker to have full remote access to the Web server that is infected by CodeRed II or CodeRed.F. Norton AntiVirus can detect an infection of CodeRed II or CodeRed.F on a Web server by detecting the payload (Trojan component) of this worm as Trojan.VirtualRoot.

Symantec Security Response has created a tool to perform a vulnerability assessment of your computer and remove the CodeRed Worm, CodeRed II and CodeRed.F. To obtain the CodeRed removal tool, please click here .



The Trojan.VirtualRoot Trojan takes advantage of a vulnerability in Windows NT and Windows 2000. Download and install the following Microsoft security patch to address that problem and to stop the Trojan from reinfecting the computer:

http://www.microsoft.com/technet/security/bulletin/MS00-052.asp

Antivirus Protection Dates

  • Initial Rapid Release version August 04, 2001
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version August 04, 2001
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date August 04, 2001

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.


Technical Description


If Trojan.VirtualRoot has modified the registry key

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\W3SVC\Parameters\Virtual Roots

(by adding a few new keys and setting the user group to 217), it allows a hacker to take full control of the Web server by sending an HTTP GET request to run scripts/root.exe on the infected Web server.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.


Removal


The CodeRed II worm and the Trojan.VirtualRoot Trojan must be removed together. For removal instructions, please read the Removal section in the CodeRed II or CodeRed.F writeups. You can download a removal tool from here .

Writeup By: Richard Cave