Backdoor.Khaos

When Backdoor.Khaos is executed, the backdoor server components of this threat:

1. Notify the client side,
2. Opens port 6,969 for listening, and
3. Waits for the commands from the remote client. These commands give a hacker access to the infected computer.

Database.exe is usually the file name of the client component (the component used by the hacker). The client component has a graphical user interface.

The hacker can use the client to activate the payload inside the server. The payload can create the batch file, C:\Windows\System\Scan.bat, which includes the commands to delete all the .dll, .exe, and .sys files from the C:\Windows\System and C:\Windows folders. Because the path names are hard-coded, the threat will most likely fail to do any damage on Windows NT, 2000, or XP systems.

The server contains some hard-coded messages. The hacker can make any of these messages display on your computer.
The five messages are:

1. You have way too much porn on your hard drive. Please delete some and restart your machine. | Error 12743:28576 FAT32
   
2. Damn you look like you got raped with the ugly stick. Get away from the monitor. Error 1K6h2a8o7s Khaos FAT32
   
3. Windows has detected a homosexual using this computer. Please become straight, restart, and try again.
   
4. Warning ! Windows has detected child pornography in the directory C:\Windows\System\Colors\Porn\ and in directory C:\America Online 6.0a\download\ | Please remove these files and restart your computer.
   
5. Khaos -N- Konfusion

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.

Summary