Backdoor.Optix

SUMMARY

Backdoor.Optix is a backdoor Trojan program that was written in the Delphi language.

Behavior

Symptoms

Transmission

Protection

• Virus Definitions (LiveUpdate™ Weekly) December 26, 2002
• Virus Definitions (Intelligent Updater) December 26, 2001

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

TECHNICAL DETAILS

Several variants of Backdoor.Optix have been discovered. All of them, when executed, open a port on the computer. This allows a hacker to connect to the computer and perform any desired actions. All variants discovered will also attempt to terminate the process for several antivirus and security products.

Some of the variants may execute additional files when the file containing Backdoor.Optix is executed. Variants that send messages using the ICQ network have also been discovered. The messages are sent to the author of the Trojan to tell them that an infected computer is online.

Many, but not all variants of Backdoor.Optix create a Winstart.bat file that can contain various commands. These commands could include recreating the Trojan if it is deleted.

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

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.Optix. If any files are detected as Backdoor.Optix, delete the Winstart.bat file before you restart the computer. For detailed information, read the section that follows.

Delete the Winstart.bat file
This is necessary only if Backdoor.Optix was detected on your computer.

Most variants of Backdoor.Optix will create a batch file named Winstart.bat in the %Windows% folder. Winstart.bat is a standard Windows file that can be created and used by programs when you install software. If the Winstart.bat file exists, it will run when you start Windows, and any commands in it will be executed.

NOTE: %Windows% is a variable. The worm locates the Windows folder (by default this is C:Windows or C:Winnt) and copies itself to that location.

Backdoor.Optix keeps a second copy of itself on the hard drive. It also may add commands to the Winstart.bat, so that if you delete the Trojan from its original location, when Winstart.bat is run, it will recreate the Trojan file. Norton AntiVirus does not detect the Winstart.bat file, because it is not by itself viral.

Therefore, if Backdoor.Optix is found on the computer, we strongly recommend that you use Windows Explorer to locate and delete the WindowsWinstart.bat file before you restart the computer. To do this:

1. Start Windows Explorer.
2. Browse to the folder where Windows is installed. By default this is C:Windows or C:Winnt.
3. Locate and delete the Winstart.bat file.