VBS_CANTIX.HV

 Analysis by: Michelle Morales

 ALIASES:

Worm:VBS/Cantix.A (Microsoft); VBS.Runauto (Symantec); Worm.VBS.Cantix.a (Kaspersky);

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Propagates via removable drives


This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It adds certain registry entries to disable the Task Manager. This action prevents users from terminating the malware process, which can usually be done via the Task Manager. It disables Task Manager, Registry Editor, and Folder Options.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size:

11,330 bytes

File Type:

VBS

Memory Resident:

Yes

Initial Samples Received Date:

04 Dec 2012

Payload:

Runs commands

Arrival Details

This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This worm drops the following copies of itself into the affected system:

  • {folders}\dekstop.ini
  • %AppDataLocal%\Microsoft\CD Burning\dekstop.ini
  • %User Profile%\My Documents\df5srvc.bfe

(Note: %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It drops the following files:

  • %System%\rad4809c.tmp --> this is a decrypted version of the original malware file
  • %System%\Serv60d.dll --> this is a blank file
  • {folders}\Microsoft.lnk
  • %System%\v.doc
  • %AppDataLocal%\Microsoft\CD Burning\autorun.inf --> currently detected as: INF_CANTIX.DSL
  • %System%\auto.exe --> currently detected as: INF_CANTIX.DSL

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Explorer = "Wscript.exe //e:VBScript "%AppDataLocal%\dekstop.ini""

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Df5serv = "Wscript.exe //e:VBScript "%User Profile%\My Documents\df5srvc.bfe""

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WinUpdate = "Wscript.exe //e:VBScript "%Windows%\:Microsoft Office Update for Windows XP.sysi"" --> this entry is added if the file system of drive C: is New Technology File System (NTFS)

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\SuperHidden

HKEY_CLASSES_ROOT\CLSID\{11111111-2222-3333-4444-555555555555} --> this key is added on the 1st day of the month

HKLM\Software\Microsoft\
Windows\CurrentVersion\explorer\
Desktop\NameSpace\{11111111-2222-3333-4444-555555555555} --> this key is added on the 1st day of the month

It adds the following registry entries:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\SuperHidden
WarningIfNotDefault = "fandy love yuyun"

HKEY_CLASSES_ROOT\CLSID\{11111111-2222-3333-4444-555555555555}
Serviks --> this entry is added on the 1st day of the month =

HKEY_CLASSES_ROOT\CLSID\{11111111-2222-3333-4444-555555555555}
DefaultIcon = "shell32.dll,48" --> this entry is added on the 1st day of the month

HKEY_CLASSES_ROOT\CLSID\{11111111-2222-3333-4444-555555555555}\
ShellFolder
Attributes = "0" --> this entry is added on the 1st day of the month

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\SuperHidden
CheckedValue = "0"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\SuperHidden
UncheckedValue = "0"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\SuperHidden
DefaultValue = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Internet Explorer\Main
Start Page = "http://www.{BLOCKED}dot.co.nr"

(Note: The default value data of the said registry entry is {default user home page}.)

It adds the following registry entries to disable the Task Manager:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = "1"

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistrytools = "1"

It deletes the following registry keys:

HKEY_CLASSES_ROOT\lnkfile\IsShortcut

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {removable drive}:\dekstop.ini

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[autorun]
open=WScript.exe //e:VBScript dekstop.ini auto
shell\open=Open
shell\open\Command=WScript.exe //e:VBScript dekstop.ini auto
shell\open\Default=1
shell\explore=Explore
shell\explore\Command=WScript.exe //e:VBScript dekstop.ini auto

NOTES:

This malware creates shortcuts under folders that points to the copy of the malware. It also tries to copy itself to as New Technology File System (NTFS) alternate data stream:

  • %Windows%\:Microsoft Office Update for Windows XP.sys

It prints the dropped file %System%\v.doc every 1st day of the following months:

  • January
  • April
  • August
  • October

This is done by running the following command:

  • notepad.exe /p "%System%\v.doc"

The content of the document that it prints is as follows:

Orang Bodoh Cari Jodoh

Dahulu terasa indah
Tak ada yang mau dan menginginkan aku
Karna cuma diriku yang tak laku-laku

Tiada yang salah
Hanya aku manusia bodoh
Yang biarkan semua ini permainkanku
Berulang ulang ulang kali


Pengumuman-pengumuman
Siapa yang mau bantu
Tolong aku kasihani aku
Tolong carikan diriku kekasih hatiku
Siapa yang mau

Mencoba bertahan sekuat hati
Layaknya karang yang
Dihempas sang ombak
Jalani hidup dalam buai belaka
Serahkan cinta tulus di dalam takdir

Hanya kepedihan
Yang s'lalu datang menertawakanku
Engkau belahan jiwa
Tega menari indah di atas tangisanku

Tapi sampai kapankah ku harus
Menanggungnya kutukan cinta ini
Bersemayam dalam kalbu

  SOLUTION

Minimum Scan Engine:

9.700

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

To enable Registry Editor, Task Manager, and Folder options:

  1. Open Notepad. To do this:
    • For Windows 2000, XP, and Server 2003 users:
      Click Start > Run, type Notepad in the text box provided, then press Enter.
    • For Windows Vista, 7, and 2008 users:
      Click Start > type Notepad, then press Enter.
    • For Windows 8, 8.1, and 2012 users:
      Right-click on the lower left corner of the screen. Click Run. Type Notepad in the input field, then press Enter.
  2. Copy and paste the following script:
  3. Save this file as C:RESTORE.VBS.
  4. Run C:\RESTORE.VBS by double-clicking on the file.
  5. Click Yes at the prompt of the message box to execute the .VBS file.

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Explorer = "Wscript.exe //e:VBScript "%AppDataLocal%\dekstop.ini""
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Df5serv = "Wscript.exe //e:VBScript "%User Profile%\My Documents\df5srvc.bfe""
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • WinUpdate = "Wscript.exe //e:VBScript "%Windows%\:Microsoft Office Update for Windows XP.sysi""

Step 6

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://www.bendot.co.nr"
      To: Start Page = {default user home page}

Step 7

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder
  • HKEY_CLASSES_ROOT\CLSID\{11111111-2222-3333-4444-555555555555}

Step 8

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • {folders}\Microsoft.lnk
  • shortcut files under different directories

Step 9

Search and delete the files detected as VBS_CANTIX.HV

*Note: Some component files may be hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the File name* input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012 (R2):

  1. Open a Windows Explorer window.
    • For Windows Vista, 7, and Server 2008 users, click Start>Computer.
    • For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen,then click File Explorer.
  2. In the Search Computer/This PC input box, type the name of the file that was detected earlier.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 10

To delete ADS files:

  1. Download Streams.exe from this Microsoft page.
  2. Extract the contents of this file to a location of your choice.
  3. Open a command prompt window. To do this:
    • On Windows 2000, XP, and Server 2003:
      Click Start>Run. In the input box, type CMD, and press Enter.
    • On Windows Vista, 7, and Server 2008:
      Click the Windows button, type CMD in the search box, and press Enter.
    • On Windows 8, 8.1, and Server 2012:
      Right-click on the lower-left corner of the screen, click Command Prompt.
  4. In the command prompt, type the following, then press Enter:
    CD {Path where contents of downloaded file was extracted}
  5. Still in the command prompt type the following then press Enter:
    Streams.exe -d
    • %Windows%\:Microsoft Office Update for Windows XP.sys
  6. Type exit then press Enter.

Step 11

Restart in normal mode and scan your computer with your Trend Micro product for files detected as VBS_CANTIX.HV. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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