Printer Friendly Page

Discovered: May 27, 2007
Updated: May 27, 2007 12:11:25 PM
Also Known As: Trojan-Spy:W32/Banker.CPV [F-Secure]
Infection Length: 76,800 bytes
Systems Affected: Windows

Infostealer.Banker.D is a Trojan horse that steals banking information and opens a back door on the compromised computer.

Antivirus Protection Dates

  • Initial Rapid Release version May 27, 2007 revision 004
  • Latest Rapid Release version July 28, 2017 revision 020
  • Initial Daily Certified version May 27, 2007 revision 009
  • Latest Daily Certified version July 29, 2017 revision 001
  • Initial Weekly Certified release date May 30, 2007

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

Writeup By: Elia Florio

Discovered: May 27, 2007
Updated: May 27, 2007 12:11:25 PM
Also Known As: Trojan-Spy:W32/Banker.CPV [F-Secure]
Infection Length: 76,800 bytes
Systems Affected: Windows

When the Trojan executes, it creates a mutex to ensure that only one instance of the Trojan is runs on the compromised computer:

Next, it drops the following DLL file:

[TROJAN BHO DLL] may be one of the following file names:

  • torm.dll
  • coman.dll
  • helper.dll
  • torm1.dll
  • coman1.dll
  • helper1.dll

It then registers the dropped DLL component as a Browser Helper Object by executing the following command:
regsvr32 /s [PATH TO TROJAN BHO DLL]

It also drops one of the following XML configuration files. The file contains details of banks to be targeted:
  • %System%\helper.sys
  • %System%\helper.xml

The Trojan then creates the following registry entries:

The Trojan will create the following registry subkeys and then delete the initial executable file:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\[PATH TO TROJAN BHO DLL]

[TROJAN BHO CSLID] may be one of the following values:
  • {60FD4F58-4748-48f6-b661-5fce71b0d907}
  • {327C3AF0-4EF6-4F8A-9A8D-685a4815D9F8}
  • {AE1AA4FA-C3A2-4c33-90CD-69DD021A35C8}

The Trojan then monitors for access to the targeted banking Web site login screens. When an access attempt is made, it injects its own HTML snippet into the HTML returned by the bank Web server. The HTML snippet injected causes the browser to display additional fields in the login form for the user to enter in details such as the PIN, Social Security Number, date of birth and so on.

When the user enters this information into the form and submits it, the Trojan will take a copy of the data and then pass on the request to the bank Web server. As a result the interception made by the Trojan is transparent and seamless to the unsuspecting user.

The Trojan may also attempt to steal other details including:
  • Windows protected storage passwords
  • Internet Explorer forms and auto-complete saved passwords
  • Email account details

Next, the Trojan opens a back door and attempts to contact one of the following remote computers on TCP port 80:

The page requested from the remote computer could be one of the following:
  • /newuser.php (used to notify the attacker of an infection)
  • /mail.php (used to send e-mail)
  • /upload.php (used to upload data to the server)
  • /command.php (used to send or receive commands)
  • /commandback.php (used to send or receive commands)

The Trojan may also create the following files to store the stolen information and to exchange commands with the remote computer:
  • %System%\wab.dat
  • %System%\ps.dat
  • %System%\cookie.dat
  • %System%\boa.dat
  • %System%\alog.txt
  • %System%\commands.xml
  • %System%\tns.dll

The back door enables the following actions to be carried out on the compromised computer depending on the commands received:
  • reboot the computer
  • download a remote file to %System%\file.exe
  • execute a program
  • load a new XML configuration file
  • uninstall the Trojan
  • delete Internet Explorer cookies
  • add a host to %System%\drivers\etc\hosts file
  • delete the files C:\ntldr and C:\ and then reboot

Writeup By: Elia Florio

Discovered: May 27, 2007
Updated: May 27, 2007 12:11:25 PM
Also Known As: Trojan-Spy:W32/Banker.CPV [F-Secure]
Infection Length: 76,800 bytes
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. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Run a full system scan.
  4. Delete any values added to the registry.

For specific details on each of these steps, read the following instructions.

1. To disable System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:

Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, reenable System Restore by following the instructions in the aforementioned documents.

For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article: Antivirus Tools Cannot Clean Infected Files in the _Restore Folder (Article ID: Q263455).

2. To update 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.

    If you use Norton AntiVirus 2006, Symantec AntiVirus Corporate Edition 10.0, or newer products, LiveUpdate definitions are updated daily. These products include newer technology.

    If you use Norton AntiVirus 2005, Symantec AntiVirus Corporate Edition 9.0, or earlier products, LiveUpdate definitions are updated weekly. The exception is major outbreaks, when definitions are updated more often.

  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted daily. You should download the definitions from the Symantec Security Response Web site and manually install them.

The latest Intelligent Updater virus definitions can be obtained here: Intelligent Updater virus definitions . For detailed instructions read the document: How to update virus definition files using the Intelligent Updater .

3. To run a full system scan
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.

    For Norton AntiVirus consumer products: Read the document: How to configure Norton AntiVirus to scan all files.

    For Symantec AntiVirus Enterprise products: Read the document: How to verify that a Symantec Corporate antivirus product is set to scan all files.

  2. Run a full system scan.
  3. If any files are detected, follow the instructions displayed by your antivirus program.
Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do this, run the scan in Safe mode. For instructions, read the document, How to start the computer in Safe Mode . Once you have restarted in Safe mode, run the scan again.
After the files are deleted, restart the computer in Normal mode and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [FILE PATH]
Message body: Windows cannot find [FILE NAME]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.

4. To delete the value from the registry
Important: 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 subkeys only. For instructions refer to the document: How to make a backup of the Windows registry .
  1. Click Start > Run.
  2. Type regedit
  3. Click OK.

    Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.
  4. Navigate to and delete the following entries:

    HKEY_LOCAL_MACHINE\Software\Helper\"DName" = "[ENCRYPTED STRING1]"
    HKEY_LOCAL_MACHINE\Software\Helper\"Dom" = "[HEX VALUES]"
    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\[TROJAN BHO CLSID]

  5. Exit the Registry Editor.

Writeup By: Elia Florio