Backdoor.Oblivion

Printer Friendly Page

Discovered: October 23, 2001
Updated: February 13, 2007 11:37:32 AM
Type: Trojan Horse


Backdoor.Oblivion is a Backdoor.Trojan that can allow unauthorized access to your computer.

Antivirus Protection Dates

  • Initial Rapid Release version October 23, 2001
  • Latest Rapid Release version March 23, 2017 revision 037
  • Initial Daily Certified version October 23, 2001
  • Latest Daily Certified version March 23, 2017 revision 041

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

Writeup By: Gor Nazaryan

Discovered: October 23, 2001
Updated: February 13, 2007 11:37:32 AM
Type: Trojan Horse


When it is run, Backdoor.Oblivion copies itself as \Windows\ZipLoader32.exe.

NOTE: ZipLoader32.exe is the most common file name, but it is not the only one. The file name can easily be changed by the hacker who is distributing the Trojan.

The Trojan then adds a reference to the dropped file in the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices

so that the Trojan runs when you start Windows.

It also may add a reference to the file in the System.ini and Win.ini files.

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: Gor Nazaryan

Discovered: October 23, 2001
Updated: February 13, 2007 11:37:32 AM
Type: Trojan Horse


To remove this Trojan, delete files detected as Backdoor.Oblivion, and remove any values that it added to the registry, or references to it from the System.ini and Win.ini files.

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. Write down the file names of any files that are detected as Backdoor.Oblivion and then delete them.

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 click Run. The Run dialog box appears.
  2. Type regedit and then click OK. The Registry Editor opens.
  3. Navigate to each of the following keys:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices
  4. In the right pane, look for lines that refer to the files, such as ZipLoader32.exe, that were detected as Backdoor.Oblivion, and delete any such values that you find.
  5. Click Registry, and then click Exit.

To edit the System.ini and Win.ini files:
This needs to be done only on computers that are running Windows 95/98/Me.

NOTE: (For Windows Me users only) Due to the file-protection process in Windows Me, a backup copy of the file that you are about to edit exists in the C:\Windows\Recent folder. We recommend that you delete this file before you continue with the steps in this section. To do this using Windows Explorer, go to C:\Windows\Recent, and in the right pane select the Win.ini file and delete it. It will be regenerated as a copy of the file that you are about to edit when you save your changes to that file.
  1. Click Start, and click Run.
  2. Type the following, and then click OK.

    edit c:\windows\win.ini

    The MS-DOS Editor opens.

    NOTE: If Windows is installed in a different location, make the appropriate path substitution.
  3. In the [windows] section of the file, look for an entry similar to the following:

    load=<name of the file that was detected as ZipLoader32.exe>
  4. Select the entire line. Be sure that you have not selected any other text; then press Delete.
  5. In the [windows] section of the file, look for a line similar to the following:

    run=<name of the file that was detected as ZipLoader32.exe>
  6. If it exists, select the entire line. Be sure that you do not select any other text; then press Delete.
  7. Click File, and click Save.
  8. Click File, and click Exit.
  9. Click Start, and click Run.
  10. Type the following, and then click OK.

    edit c:\windows\win.ini

    The MS-DOS Editor opens.

    NOTE: If Windows is installed in a different location, make the appropriate path substitution.
  11. In the [boot]section of the file, look for an entry that refers to the file that was detected as ZipLoader32.exe. Delete this reference.

    NOTE:
    If the reference is part of the line

    shell=explorer.exe

    delete only the text to the right of the .exe, so that, when you are done, this line reads only:

    shell=explorer.exe
  12. Click File, and click Save.
  13. Click File, and click Exit.


Writeup By: Gor Nazaryan