Backdoor.Systsec

SUMMARY

Backdoor.Systsec is a backdoor Trojan horse. It listens on port 1034 and allows unauthorized access to an infected computer. It sets itself up to run automatically when Windows restarts.

Protection

• Virus Definitions (LiveUpdate™ Weekly) February 13, 2002
• Virus Definitions (Intelligent Updater) February 13, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low

Distribution

• Distribution Level: Low
• Ports: 1034

TECHNICAL DETAILS

If more than one instance of Backdoor.Systsec is run, the new one opens the next higher numbered port.

To enable itself to run at startup, it adds the value:

SystSecure32 SystSecure32.exe      

to the following registry key:

HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun

Recommendations

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

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended 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 (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• 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.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. 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.

REMOVAL

Delete all files that are detected as Backdoor.Systsec and remove the value that it added to the registry.

To remove the Trojan:

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
3. Run a full system scan.
4. Delete all files that are detected as Backdoor.Systsec.

To edit the registry:

CAUTION: We strongly recommend that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to back up the Windows registry for instructions.

1. Click Start, and then click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the following key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the following value:
   
   SystSecure32 SystSecure32.exe
   
5. Click Registry, and then click Exit.