Infostealer.Bancos.Z

Printer Friendly Page

Discovered: July 13, 2005
Updated: February 13, 2007 12:54:26 PM
Also Known As: PWSteal.Bancos.Z
Type: Trojan Horse
Systems Affected: Windows


Infostealer.Bancos.Z is a Trojan horse that steals passwords and logs keystrokes entered into certain financial Web sites.

NOTE : Definitions prior to May 10, 2006 may detect this threat as PWSteal.Bancos.Z

Antivirus Protection Dates

  • Initial Rapid Release version July 13, 2005
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version July 13, 2005
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date July 13, 2005

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

Writeup By: Candid Wueest

Discovered: July 13, 2005
Updated: February 13, 2007 12:54:26 PM
Also Known As: PWSteal.Bancos.Z
Type: Trojan Horse
Systems Affected: Windows


When Infostealer.Bancos.Z is executed, it performs the following actions:

  1. Creates the following hidden file:

    %System%\svcsys.dll

    Note: %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP)

  2. Checks for the presence of the value:

    "SvcSys" = "[RANDOM CLSID]"

    in the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad

    Note: [RANDOM CLSID] could be {FCF39D40-4CAB-49B4-B6F4-955EC73FD3B3}

  3. Checks for the presence of the value:

    "(Default)" = "svcsys.dll"

    in the subkey:

    HKEY_CLASSES_ROOT\CLSID\[RANDOM CLSID]\InprocServer32

  4. Creates the above registry entries, if they don't exist.

  5. Deletes the above registry entries, if they do exist, and creates the file %System%\[FILE NAME].exe.

    The Trojan will then add the value:

    "SvcSys" = "%System%\[FILE NAME].exe"

    to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    so that it is executed everytime Windows starts.

  6. Launches the Windows system process, svchost.exe and loads svcsys.dll.

  7. Deletes its original file and %System%\[FILE NAME].exe, if it exists.

  8. Monitors open window titles and any text strings input into Internet Explorer.

  9. Searches user entered text strings for text that matches one of following keywords:

    • bank
    • banc
    • banco
    • singin
    • online
    • ANZ Internet Banking - Logon
    • ANZ E*Trade
    • commbank.com.au
    • Westpac online
    • Business Online
    • ib.national.com.au
    • Bienvenido
    • Banesto
    • bank
    • banc
    • banco
    • online

  10. Attempt to display the following text in Portuguese or English, asking the user to type in their online bank logon credentials:

    Message:
    Dear Internet Bank User!

    We recognize the importance of protecting your personal and financial information and for  security purposes we have entered additional checking. The personal information that we obtain about you assists us in servicing your account. Your personal information is used primarily as a way of authenticating you as the proper owner
    of your account and as the person who can made payments. We protect your account information. That's why you have to enter a unique MEMORABLE INFORMATION.
    Please input your MEMORABLE INFORMATION.

  11. Logs information entered and stores it in the file %System%\dllsys.dll.

  12. Sends the file to one of the following URLs:

    • [http://]vladivostok2000.info/log/[REMOVED]/log.php
    • [http://]azalos.com/log/[REMOVED]/log/php

      or sends it by email to predetermined email on the rambler.ru domain.

  13. Attempts to modify the following registry subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters
    \FirewallPolicy\StandardProfile\AuthorizedApplications\List

    in an attempt to bypass the firewall.

  14. Attempts to periodically update itself by downloading %Temp%\222.exe from the following URL:

    [http://]vladivostok2000.info/[REMOVED]

    Note: %Temp% is a variable that refers to the Windows temporary folder. By default, this is C:\Windows\TEMP (Windows 95/98/Me/XP) or C:\WINNT\Temp (Windows NT/2000)


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: Candid Wueest

Discovered: July 13, 2005
Updated: February 13, 2007 12:54:26 PM
Also Known As: PWSteal.Bancos.Z
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. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Run a full system scan and delete all the files detected.
  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: 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 Virus Definitions (LiveUpdate).
  • 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. To determine whether definitions for this threat are available by the Intelligent Updater, refer to Virus Definitions (Intelligent Updater).

    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 scan for and delete 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, click Delete.

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 the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad

  5. In the right pane, delete the value:

    "SvcSys" = "[RANDOM CLSID]"

  6. Navigate to the subkey:

    HKEY_CLASSES_ROOT\CLSID\[RANDOM CLSID]\InprocServer32

  7. In the right pane, delete the value:


    "(Default)" = "svcsys.dll"

  8. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  9. In the right pane, delete the value, if it exists:

    "SvcSys" = "%System%\[FILE NAME].exe"

  10. Exit the Registry Editor.


Writeup By: Candid Wueest