Backdoor.Bionet.40a

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Discovered: July 04, 2001
Updated: February 13, 2007 11:36:44 AM
Type: Trojan Horse


Backdoor.Bionet.40a is a malicious backdoor Trojan. Its actions are similar to SubSeven, Netbus, and BackOrifice in that it allows unauthorized access to an infected computer.

Antivirus Protection Dates

  • Initial Rapid Release version July 05, 2001
  • Latest Rapid Release version March 03, 2008 revision 035
  • Initial Daily Certified version July 05, 2001
  • Latest Daily Certified version March 03, 2008 revision 037

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

Writeup By: Serghei Sevcenco

Discovered: July 04, 2001
Updated: February 13, 2007 11:36:44 AM
Type: Trojan Horse


Backdoor.Bionet.40a is a backdoor Trojan that runs as a server application and allows unauthorized access to an infected computer. When executed, it performs the following actions:

  1. To make itself unnoticable even on slow computers, it assigns itself the lowest thread priority value.
  2. To remove itself from the Applications list in the Windows Task Manager, it registers itself as a Service process. This permits the Trojan to continue to run even after you log off.
  3. It copies itself as \Windows\System\Procmon.exe.
  4. To enable itself to run at startup, it adds the value

    procmon       \Windows\System\procmon.exe

    to the registry key

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  5. Next, Backdoor.Bionet.40a sends the message Victim is Online to the ICQ pager of the virus author. This tells the remote computer that the infected computer is ready for remote administration.
  6. It then starts to accept and perform the remote commands from the client program through the configurable port. The remote administrator has full access to the file system of the infected computer. The Trojan permits the remote administrator to download or upload files from the remote computer, change the registry, and run commands and programs.

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: Serghei Sevcenco

Discovered: July 04, 2001
Updated: February 13, 2007 11:36:44 AM
Type: Trojan Horse


To remove the Backdoor.Bionet.40a, please follow the instructions in the order given.

To remove the Trojan:

    1. Run LiveUpdate to make sure that you have the most recent virus definitions.
    2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
    3. Delete any files detected as Backdoor.Bionet.40a. What you do next depends on whether NAV was able to delete files that it detected as infected with Backdoor.Bionet.40a:
    • If NAV was able to delete all the files that it detected as infected, go to the section To edit the registry.
    • If NAV was not able to delete all files that it detected as infected, go on to the next section and see the instructions for your operating system.

To remove files that cannot be deleted by NAV:

Follow the instructions for your version of Windows only if NAV could not delete files that it detected as infected with Backdoor.Bionet.40a.
  • Windows 95/98/Me
    1. Restart the computer in Safe Mode. For instructions on how to restart in Safe Mode, see the document How to restart Windows 9x or Windows Me in Safe Mode.
    2. Run the scan again, and delete any files detected as Backdoor.Bionet.40a.
    3. When the scan is finished, go on to the section To edit the registry.
  • Windows NT/2000
    1. Press Ctrl+Alt+Delete one time.
    2. Click Task Manager.
    3. Click the Processes tab.
    4. Click the "Image Name" column header two times to sort the processes alphabetically.
    5. Scroll through the list and look for Procmon.exe. If you find the file, click it and then click End Process.
    6. Close the Task Manager.
    7. Run the scan again, and delete any files detected as Backdoor.Bionet.40a.
    8. When the scan is finished, go on to the section To edit the registry.

To edit the registry:

CAUTION : We strongly recommend that you back up the system registry before making any changes. Incorrect changes to the registry could result in permanent data loss or corrupted files. Please make sure you modify only the keys specified. Please see the document How to back up the Windows registry before proceeding.

  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 the key

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  4. In the right pane, delete the value

    procmon
  5. Close the Registry Editor.


Writeup By: Serghei Sevcenco