WORM_ESFURY.SMC


 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:

Via network shares, Downloaded from the Internet, Dropped by other malware

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

It modifies certain registry entries to disable Security Center functions. Doing this allows this malware to execute its routines without being detected. It disables Task Manager, Registry Editor, and Folder Options.

  TECHNICAL DETAILS

File Size:

743,368 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

25 Feb 2015

Payload:

Connects to URLs/IPs

Arrival Details

This worm arrives by accessing affected shared networks.

It 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:

  • %User Profile%\{random characters}\winlogon.exe
  • %Start Menu%\Fax y Escáner de Windows.exe
  • %Start Menu%\Programs\Internet Explorer.exe
  • %User Startup%\Windows Anytime Upgrade.exe - part of autostart technique
  • %All Users Profile%\Start Menu\Windows DVD Maker.exe
  • %All Users Profile%\Start Menu\Programs\Windows Media Center.exe
  • %All Users Profile%\Start Menu\Programs\Startup\Windows Update.exe - part of autostart technique
  • %User Temp%\{random characters}\FOTOS\{Random Picture File Name}.jpg.pif
  • %User Temp%\{random characters}\JUEGOS\{Random Game File Name}.com
  • %User Temp%\{random characters}\LIBROS\{Random Book File Name}.doc.pif
  • %User Temp%\{random characters}\MUSICA\{Random Music File Name}.mp3.pif
  • %User Temp%\{random characters}\PELICULAS\{Random Movie File Name}.avi.pif
  • %User Temp%\{random characters}\PROGRAMAS\{Random Program File Name}.exe

It creates the following folders:

  • %User Profile%\{random characters}
  • %User Temp%\{random characters} - network shared folder
  • %User Temp%\{random characters}\FOTOS - network shared folder
  • %User Temp%\{random characters}\JEUGOS - network shared folder
  • %User Temp%\{random characters}\MUSICA - network shared folder
  • %User Temp%\{random characters}\PELICULAS - network shared folder
  • %User Temp%\{random characters}\PROGRAMAS - network shared folder
  • %User Temp%\{random characters}\LIBROS - network shared folder

(Note: %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.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

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
{random characters} = "%User Profile%\{random characters}\winlogon.exe"

It adds the following Image File Execution Options registry entries to automatically execute itself whenever certain applications are run:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
.exe
Debugger = ""%User Profile%\{random characters}\winlogon.exe""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{random application name}.exe
Debugger = ""%User Profile%\{random characters}\winlogon.exe""

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\System
DisableCMD = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
HideSCAHealth = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoRun = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFile = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Default_Search_URL = "http://{random characters}.directorio-w.com"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Default_Page_URL = "http://{random characters}.directorio-w.com"

HKEY_CURRENT_USER\Software\Microsoft\
Windows Script Host\Settings
Enabled = 0

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows Script Host\Settings
Enabled = 0

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Local Page = "http://{random characters}.directorio-w.com"

(Note: The default value data of the said registry entry is set by the user.)

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://{random characters}.directorio-w.com"

(Note: The default value data of the said registry entry is set by the user.)

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Search Page = "http://{random characters}.directorio-w.com"

(Note: The default value data of the said registry entry is set by the user.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = 3

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

It modifies the following registry entries to disable Security Center functions:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = 1

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = 1

(Note: The default value data of the said registry entry is 0.)

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
DisableTaskMgr = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = 0

It deletes the following registry keys:

HKEY_CLASSES_ROOT\lnkfile
IsShortcut = ""

HKEY_CLASSES_ROOT\piffile
IsShortcut = ""

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lnkfile
IsShortcut = ""

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
piffile
IsShortcut = ""

Other Details

This worm connects to the following possibly malicious URL:

  • http://{BLOCKED}s.amung.us/swidget/{random characters}
  • htttp://{BLOCKED}s.amung.us/small/00/25.png

NOTES:

Propagation

It allows the network shared folder %User Temp%\{random characters} be accessed as \\{network ip}\iTODO. The following are the subfolders and network shared folder:

  • %User Temp%\{random characters}\FOTOS accessible as \\{network ip}\iFOTOS
  • %User Temp%\{random characters}\JUEGOS accessible as \\{network ip}\iJUEGOS
  • %User Temp%\{random characters}\LIBROS accessible as \\{network ip}\iLIBROS
  • %User Temp%\{random characters}\MUSICA accessible as \\{network ip}\iMUSICA
  • %User Temp%\{random characters}\PELICULAS accessible as \\{network ip}\iPELICULAS
  • %User Temp%\{random characters}\PROGRAMAS accessible as \\{network ip}\iPROGRAMAS

It uses various filenames per folder for each copy of itself and having different file sizes.

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.503.00

FIRST VSAPI PATTERN DATE:

26 Feb 2015

VSAPI OPR PATTERN File:

11.504.00

VSAPI OPR PATTERN Date:

26 Feb 2015

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
    • {random characters} = "%User Profile%\{random characters}\winlogon.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\.exe
    • Debugger = ""%User Profile%\{random characters}\winlogon.exe""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\{random application name}.exe
    • Debugger = ""%User Profile%\{random characters}\winlogon.exe""
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\System
    • DisableCMD = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • HideSCAHealth = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • NoRun = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • NoFile = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Default_Search_URL = "http://{random characters}.directorio-w.com"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Default_Page_URL = {return user settings}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows Script Host\Settings
    • Enabled = 0
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows Script Host\Settings
    • Enabled = 0

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
    • Local Page = "{Restore prefered home page url}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Start Page = "%System%\blank.htm"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Search Page = "{Restore prefered search page url}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • Hidden = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • HideFileExt = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusDisableNotify = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • FirewallDisableNotify = 0

Step 7

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • %User Profile%\{random characters}
  • %User Temp%\{random characters}

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.
  • %Start Menu%\Fax y Escáner de Windows.exe
  • %Start Menu%\Programs\Internet Explorer.exe
  • %User Startup%\Windows Anytime Upgrade.exe
  • %All Users Profile%\Start Menu\Windows DVD Maker.exe
  • %All Users Profile%\Start Menu\Programs\Windows Media Center.exe
  • %All Users Profile%\Start Menu\Programs\Startup\Windows Update.exe

Step 9

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_ESFURY.SMC. 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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