Discovered: December 22, 2006
Updated: February 13, 2007 1:02:58 PM
Type: Worm
Systems Affected: Windows


W32.Tasnab is a worm that spreads through mapped network drives.

Antivirus Protection Dates

  • Initial Rapid Release version December 23, 2006
  • Latest Rapid Release version March 01, 2011 revision 037
  • Initial Daily Certified version December 23, 2006
  • Latest Daily Certified version March 02, 2011 revision 002
  • Initial Weekly Certified release date December 27, 2006

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

Writeup By: Eduardo Tang

Discovered: December 22, 2006
Updated: February 13, 2007 1:02:58 PM
Type: Worm
Systems Affected: Windows


When W32.Tasnab is executed, it performs the following actions:

  1. Copies itself as the following files:

    • %UserProfile%\Application Data\[CURRENT USER NAME].exe
    • %UserProfile%\Application Data\taliban.exe

      Note: %UserProfile% is a variable that refers to the current user's profile folder. By default, this is C:\Documents and Settings\[CURRENT USER] (Windows NT/2000/XP).

  2. Copies itself to the current folder and any folders accessed on drives A to Z, using one of the following names:

    • [RANDOM]Cinta Untuk Siti .exe
    • [RANDOM]Yakin Radja Band .exe
    • [RANDOM]Karena Wanita Ingin Dimengerti Ada Band .exe
    • [RANDOM]Cerita Dian Sastrowardoyo .exe
    • [RANDOM]Tutor Sex .exe
    • [RANDOM]Binalnya Tante Yenni .exe
    • [RANDOM]Cerita Malam Pertama .exe
    • [RANDOM]MyHeart Irwansyah Acha .exe
    • [RANDOM]Misteri Vagina .exe
    • [RANDOM]Pecinta Wanita Irwansyah .exe
    • [RANDOM]Sex dan Remaja .exe
    • [RANDOM]Pelajaran Sex .exe
    • [RANDOM]Dealova Once .exe
    • [RANDOM]Tokoh - tokoh dunia yang maniak sex .exe
    • [RANDOM]Pengalaman melihat kuntilanak .exe
    • [RANDOM]Surat cintaku .exe
    • [RANDOM]Surat penolakan cinta .exe
    • [RANDOM]Akte kelahiran .exe
    • [RANDOM]Perjanjian Setan .exe
    • [RANDOM]Syair Cinta Khalil Gibran .exe
    • [RANDOM]Lagu Kenangan Koes Plus .exe
    • [RANDOM]Daftar Koruptor .exe
    • [RANDOM]Cinta Buka Disini .exe
    • [RANDOM]Jangan Ah Malu .exe
    • [RANDOM]Surat Cintaku Yang Pertama .exe
    • [RANDOM]Unsur2x Vagina .exe
    • [RANDOM]Unsur2x Penis .exe
    • [RANDOM]Perbedaan Wanita dan Pria .exe
    • [RANDOM]Perjanjian Cinta .exe
    • [RANDOM]Tak ada perjanjian dalam cinta .exe
    • [RANDOM]Cinderela temukan sang Pangeran .exe
    • [RANDOM]Makalah A Einsten .exe
    • [RANDOM]Cerita Sex Untuk Anak Perempuan .exe
    • [RANDOM]Ah Sakit Bang .exe
    • [RANDOM]Taklukan Hati Perempuan .exe
    • [RANDOM]Hancurkan Keteguhan Laki laki .exe
    • [RANDOM]Lembutnya Hati Wanita .exe
    • [RANDOM]Cinta Wanita .exe
    • [RANDOM]Baca ini jika mencintaiku .exe
    • [RANDOM]Bias bias cinta .exe
    • [RANDOM]Jangan khianati aku .exe
    • [RANDOM]Lamaran Pekerjaan .exe
    • [RANDOM]Daftar Riwayat Hidup .exe
    • [RANDOM]Perjalanan Hidup Pelacur Jalanan .exe
    • [RANDOM]Surga Atau Neraka .exe
    • [RANDOM]Rahasia Pribadi .exe
    • [RANDOM]* .exe
    • [RANDOM]Proposal Miss Universe .exe
    • [RANDOM]Miss Universe VS FPI .exe
    • [RANDOM]Pendaftaran Miss Universe .exe
    • [RANDOM]Kumpulan Lagu Ungu .exe
    • [RANDOM]Naluri Lelaki Samson .exe
    • [RANDOM]Green Day Basket Case .exe
    • [RANDOM]Green Day Insomniac .exe
    • [RANDOM]Kumpulan Album Naff .exe
    • [RANDOM]The Best Of Peter Pan .exe
    • [RANDOM]The Best Of Dewa 19 .exe
    • [RANDOM]Rahasia Wanita .exe
    • [RANDOM]Pengalaman Sexku .exe
    • [RANDOM]Aku Kamu dan Dia .exe
    • [RANDOM]Lagu lagu Radja 2006 .exe
    • [RANDOM]My-Heart .exe
    • [RANDOM]Daya Magis Vagina .exe
    • [RANDOM]Cara menjadi kaya .exe
    • [RANDOM]Perwujudan Setan .exe
    • [RANDOM]New Folder .exe
    • [RANDOM]Kirana dalam cinta .exe
    • [RANDOM]Maukah kau jadi pacarku .exe
    • [RANDOM]Drain You Nirvana .exe
    • [RANDOM]Smell Like Teen Spirit Nirvana .exe
    • [RANDOM]Betapa Cintaku .exe
    • [RANDOM]Besarnya Cinta .exe
    • [RANDOM]Buku Harianku .exe
    • [RANDOM]Jadikan Aku Sephiamu .exe
    • [RANDOM]Surat Untuk Emi .exe
    • [RANDOM]Surat Untuk Eni .exe
    • [RANDOM]Surat Untuk Lydia .exe
    • [RANDOM]Surat Untuk Tania .exe
    • [RANDOM]Surat Untuk Ani .exe
    • [RANDOM]Cintanya Siti .exe
    • [RANDOM]Siti Cinta Pertama .exe
    • [RANDOM]Siti Haryani Cinta Pertama .exe
    • [RANDOM]Siti H Pacarku .exe
    • [RANDOM]Kenanganku Terindah .exe
    • [RANDOM]Kisah Cinta Terlucu .exe
    • [RANDOM]Penghianatan Dian S .exe
    • [RANDOM]Inilah Aku .exe
    • [RANDOM]Inikah Rasanya Cinta .exe
    • [RANDOM]Nikmat Sex Party .exe
    • [RANDOM]Naluri Sex Wanita .exe
    • [RANDOM]Naluri Sex Pria .exe
    • [RANDOM]Nikmat Perselingkuhan .exe

      where [RANDOM] is any text entered into the address bar in Windows Explorer.

  3. Adds the value:

    "shell" = "%UserProfile%\Application Data\taliban.exe"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

    so that it executes when windows starts.

  4. Adds the values:

    "[CURRENT USER NAME]_bangst" = "%UserProfile%\Application Data\[CURRENT USER NAME].exe"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

    so that it executes when Windows starts.

  5. Modifies the values:

    "FullPath"= "1"
    "FullPathAddress" = "1"

    in the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\CabinetState

  6. Modifies the values:

    "Hidden" = "0"
    "HideFileExt" = "0"

    in the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced

  7. Modifies the values:

    "CheckedValue" = "1"
    "DefaultValue" = "1"

    in the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL

  8. Modifies the values:

    "CheckedValue" = "2"
    "DefaultValue" = "2"

    in the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\NOHIDDEN

  9. Modifies the value:

    "NoFolderOptions" = "1"

    in the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer

  10. Creates the following files:

    • %System%\oeminfo.ini
    • %System%\oemlogo.bmp

      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).

  11. Creates the following file:

    %UserProfile%\My Documents\As Slam Bey.txt

  12. Opens As Slam Bey.txt with the default text file viewer, displaying the following message:

    **************************************************************************
    * Cinta telah menyatukan [REMOVED] nyatukan cinta kita berdua.

    Pade[REMOVED]rat 26 September 2006 16:45 wib

    A[REMOVED]Y

  13. Monitors windows where their class names match any of the following:

    • ExploreWClass
    • WorkerA
    • WorkerW
    • ReBarWindow32
    • ComboBoxEx32
    • ComboBox
    • Edit
    • IEFrame
    • Navigation Bar
    • Address Band Root
    • CabinetWClass
    • ata*
    • RegEdit_RegEdit
    • Registry Editor
    • #32770
    • System Configuration Utility
    • ThunderRT6FormDC
    • HijackThis - v1.99.0
    • Tfrmmainstartup
    • Quick StartUp
    • Pocket Killbox 0 Items
    • Show/Kill Running Process
    • Startup Guard - Found New App At Startup !
    • SysListView32
    • Autostart And Process Viewer
    • tty
    • MS-DOS Prompt
    • KILLVB
    • ConsoleWindowClass
    • Command Prompt
    • PROCEXPL
    • TfrmIntegrator
    • TuneUp Utilities
    • iKnowPS
    • CurrProcessClass
    • CurrProcess
    • Run
    • Windows Task Manager
    • Processes

  14. Monitors the Windows Explorer address bar, then duplicates itself with names consisting of the first 3 characters typed in the address bar and one of the above names.

  15. Ends the command prompt and regedit.


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: Eduardo Tang

Discovered: December 22, 2006
Updated: February 13, 2007 1:02:58 PM
Type: Worm
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. 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 run a full system scan
  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, 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 the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

  5. In the right pane, delete the value:

    "shell" = "%UserProfile%\Application Data\taliban.exe"

  6. Navigate to the subkey:

    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  7. In the right pane, delete the value:

    "[CURRENT USER NAME]_bangst" = "%UserProfile%\Application Data\[CURRENT USER NAME].exe

  8. Restore the values for the following registry entries to their previous settings:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\CabinetState\"FullPath" = "1"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\CabinetState\"FullPathAddress" = "1"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\"Hidden" = "0"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\"HideFileExt" = "0"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL\"CheckedValue" = "1"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL\"DefaultValue" = "1"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\NOHIDDEN\"CheckedValue" = "2"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\NOHIDDEN\"DefaultValue" = "2"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\"NoFolderOptions" = "1"

  9. Exit the Registry Editor.


Writeup By: Eduardo Tang