Backdoor.OptixPro.13b

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Discovered: January 21, 2004
Updated: February 13, 2007 12:16:33 PM
Also Known As: Backdoor.Optix.Pro.13 [Kaspers
Type: Trojan Horse
Systems Affected: Windows


Backdoor.OptixPro.13b is a Trojan horse that gives a remote attacker full remote access to your computer. By default, the Trojan opens port 3410 for listening.

Antivirus Protection Dates

  • Initial Rapid Release version January 22, 2004
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version January 22, 2004
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date January 26, 2004

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

Writeup By: Paul Mangan

Discovered: January 21, 2004
Updated: February 13, 2007 12:16:33 PM
Also Known As: Backdoor.Optix.Pro.13 [Kaspers
Type: Trojan Horse
Systems Affected: Windows



Backdoor.OptixPro.13b is a minor variant of Backdoor.OptixPro.13 , with additional features designed to complicate detection and removal.

Backdoor.OptixPro.13b can be configured to perform any or all of the following actions:

Files
Backdoor.OptixPro.13b copies itself to either the %Windir% or %System% folder as <name of original Trojan file> and <name of shell hook file>. This action varies and depends on the configuration settings in the Trojan.


Note:
  • %Windir% is a variable: The Trojan locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location.
  • %System% is a variable: The Trojan locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
  • <name of original Trojan file> represents the file name of the Trojan. The attacker selects this.
  • <name of shell hook file> represents the file name of the Trojan when handling the execution of the .exe files. The attacker also selects this.



Registry autostart

Backdoor.OptixPro.13b creates a string value under the registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices

so that Backdoor.OptixPro.13b is executed each time you start Windows.

This registry value is of the form:

"<registry value name>"="<path to trojan file>"

The attacker chooses the <registry value name>.

Registry shell hook
Backdoor.OptixPro.13b hooks the execution of the executable files, by changing the (Default) value of the registry key:

HKEY_CLASSES_ROOT\exefile\shell\open\command

to:

<path to shell hook file as>


Registry RAS settings
Backdoor.OptixPro.13b modifies the behavior of the computer when connected to a modem, by changing the registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\Current\Software\Microsoft\Windows\CurrentVersion\Internet Settings\EnableAutoDial

to:

0

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Internet Settings\EnableAutoDial

to:

0

HKEY_LOCAL_MACHINE\Software\Microsoft\RAS Autodial\Control\DisableConnectionQuery

to:

1

HKEY_LOCAL_MACHINE\Software\Microsoft\RAS Autodial\Control\LoginSessionDisable

to:

1


System files

Backdoor.OptixPro.13b modifies the Run= line of the Win.ini file to:

Run=<path to trojan file>

as well as the Shell= line of the System.ini file to:

Shell=Explorer.exe <path to trojan file>


Ports
Backdoor.OptixPro.13b opens a listening port on port 3410. (This is the default port, but the attacker can configure the Backdoor Trojan to any other port.)


Functionality
Backdoor.OptixPro.13b allows the attacker to do the following:


Evasion options
  • Hide files from the user
  • Hide registry keys from the user

Notification options
An attacker can be notified that the backdoor has been installed by a number of different methods.
  • SMTP email
  • HTTP request
  • Instant messaging notification (IRC, MSN, or ICQ)

Power options
  • Log off the current user
  • Restart the system
  • Shut down the system
  • Suspend the system
  • Crash the system, causing a blue screen to appear


Backdoor information
Obtain information about the running Trojan


File system
  • Upload and download files
  • Execute files
  • Create folders
  • Delete files and folders
  • Rename files and folders


Processes
  • List running processes
  • Stop running process


Windows tasks
  • Minimize windows
  • Maximize windows
  • Change the title of windows
  • Close windows
  • Send keystrokes to specific windows


Registry
  • Create new values and keys
  • Edit values
  • Delete values and keys


FTP server
Launch an FTP server on a specified port.


IP scanner
Launch a <IP range>:port scan from a compromised system for the open ports.


Port redirection
Redirect connections to a compromised system on a specific port to another computer and port.


System information
  • Acquire system information, such as the owner, OS version, and key and CPU type and speed
  • Steal cached passwords
  • Steal AIM passwords
  • Steal RAS passwords


System monitoring
  • Provide a live feed of the system screen
  • Provide a live feed through the system Webcam
  • Launch a keylogger


Other
  • Open and close the CD-ROM drive
  • Show and hide the clock
  • Turn the monitor on and off
  • Start and stop the screensaver
  • Enable and disable the mouse and keyboard
  • Produce beeping sounds from the computer's speaker


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.

Writeup By: Paul Mangan

Discovered: January 21, 2004
Updated: February 13, 2007 12:16:33 PM
Also Known As: Backdoor.Optix.Pro.13 [Kaspers
Type: Trojan Horse
Systems Affected: Windows



The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Update the virus definitions.
  2. Reverse the changes made to the registry.
  3. Reverse the changes made to the Win.ini and System.ini files (Windows 95/98/Me).
  4. Run a full system scan and delete all the files detected as Backdoor.OptixPro.13b.
For specific details on each of these steps, read the following instructions.

1. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
  • Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).

    The Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

2. Reversing the changes made to the registry
The backdoor can hide some files and registry keys and it modifies the registry so that it runs when you start any .exe files.
Consequently, you should restart the computer in Safe mode or VGA mode before attempting to change the registry keys or scan for files.
  1. Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
    • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
    • For Windows NT 4 users, restart the computer in VGA mode.
  2. Make a copy of the Registry Editor as a file with the .com extension, and then run that particular file.

    Do one of the following, depending on the version of Windows you are running:
    • Windows 95/98 users
      1. Click Start.
      2. Point to Programs.
      3. Click the MS-DOS Prompt. (A DOS window opens at the C:\Windows prompt.) Proceed to step C of this section.

    • Windows Me users
      1. Click Start.
      2. Point to Programs.
      3. Point to Accessories.
      4. Click the MS-DOS Prompt. (A DOS window opens at the C:\Windows prompt.) Proceed to step C of this section.

    • Windows NT 4.0/2000 users
      1. Click Start, and then click Run.
      2. Type command, and then press Enter. (A DOS window opens.)
      3. Type cd \winnt, and then press Enter.
      4. Go to step C of this section.

    • Windows XP users
      1. Click Start, and then click Run.
      2. Type command, and then press Enter. (A DOS window opens.)
      3. Type the following:

        cd\
        cd \windows

        Press Enter after typing each one.
      4. Proceed to step C of this section.

  3. Type copy regedit.exe regedit.com

    and then press Enter.

  4. Type start regedit.com

    and then press Enter. (The Registry Editor opens in front of the DOS window.)

    After you finish editing the registry, exit the Registry Editor, and then exit the DOS window as well.

  5. Before continuing, Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. For instructions, read the document, "How to make a backup of the Windows registry."

  6. Navigate to and select the key:

    HKEY_CLASSES_ROOT\exefile\shell\open\command

    NOTE: The HKEY_CLASSES_ROOT key contains many subkey entries that refer to other file extensions. One of these file extensions is .exe. Changing this extension can prevent any files ending with a .exe extension from running. Make sure that you completely browse through this path until you reach the \command subkey.

    Modify the HKEY_CLASSES_ROOT\exefile\shell\open\command subkey, shown in the following figure:

    <<=== NOTE: Modify this key.

  7. In the right pane, double-click the (Default) value.

  8. Delete the current value data, and then type:

    "%1" %*

    That is, type the characters: quote-percent-one-quote-space-percent-asterisk.


    NOTES
    • Under Windows 95/98/Me/NT, the Registry Editor automatically encloses the value within quotation marks. When you click OK, the (Default) value should look exactly like this:

      ""%1" %*"  
    • Under Windows 2000/XP, the additional quotation marks will not appear. When you click OK, the (Default) value should look exactly like this:

      "%1" %*
    • Make sure that you completely delete all the value data in the command key before typing the correct data. If you leave a space at the beginning of the entry, any attempt to run the program files will result in the error message, "Windows cannot find .exe." If this occurs, restart the entire process from the beginning of this section and make sure that you completely remove the current value data.

  9. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  10. In the right pane, delete the value:

    <registry value name> %system%\<name of original Trojan file>

  11. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  12. In the right pane, delete the value:

    <registry value name> %system%\<name of original Trojan file>

  13. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    RunServices

    NOTE: This key is not found on all the computers.

  14. In the right pane, delete the value:

    <registry value name> %system%\<name of original Trojan file>

  15. Navigate to the key:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\Current\Software\Microsoft\Windows\CurrentVersion\
    Internet Settings\

  16. In the right pane, you can modify the value of:

    EnableAutoDial

    to:

    1

    Note: This value should be left at 0, unless you are familiar with the effect of modifying it.

  17. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
    Internet Settings\

  18. In the right pane, you can modify the value of:

    EnableAutoDial

    to:

    1

    Note: This value should be left at 0, unless you are familiar with the effect of modifying it.

  19. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\RAS Autodial\Control\

  20. In the right pane, you can modify the value of:

    DisableConnectionQuery

    to:

    0

  21. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\RAS Autodial\Control\

  22. In the right pane, you can modify the value of:

    LoginSessionDisable

    to:

    0

    Note: This value should be left at 1, unless you are familiar with the effect of modifying it.

  23. Exit the Registry Editor.

3. Reversing the changes made to the Win.ini and System.ini files
If you are running Windows 95/98/Me, follow these steps:
  1. The function you perform depends on your operating system:
    • Windows 95/98: Go to step B.
    • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made backup copies of the System.ini and Win.ini files, which you need to edit. If these backup copies exist, they will be in the C:\Windows\Recent folder. Symantec recommends that you delete the files before continuing with the steps in this section. To do this:
      1. Start Windows Explorer.
      2. Browse to and select the C:\Windows\Recent folder.
      3. In the right pane, select the System.ini and Win.ini files and delete them. Windows will regenerate the files.

  2. Click Start, and then click Run.

  3. Type the following:

    edit c:\windows\win.ini

    and then click OK. (The MS-DOS Editor opens.)

    NOTE: If Windows is installed in a different location, make the appropriate path substitution.

  4. In the [windows] section of the file, look for a line similar to:

    Run=%System%\<name of original Trojan file>

  5. If this line exists, delete the entire line.

  6. Click File, and then click Save.

  7. Click File, and then click Exit.

  8. Click Start, and then click Run.

  9. Type the following:

    edit c:\windows\system.ini

    and then click OK. (The MS-DOS Editor opens.)

    NOTE: If Windows is installed in a different location, make the appropriate path substitution.

  10. In the [boot] section of the file, look for a line similar to:

    shell=Explorer.exe <name of Trojan file>

  11. If this line exists, delete everything to the right of Explorer.exe.

    When you are done, it should look like:

    shell=Explorer.exe

  12. Click File, and then click Save.

  13. Click File, and then click Exit.
4. Scanning for and deleting the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with Backdoor.OptixPro.13b, click Delete.
  4. Restart the computer in Normal mode.


Writeup By: Paul Mangan