Analysis by: Anthony Joe Melgarejo
ALIASES:

Worm:Win32/Mogoogwi.B (Microsoft), W32.Ippedo (Symantec)

 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: Propagates via removable drives, Propagates via network shares

This worm arrives by connecting affected removable drives to a system. It arrives by accessing affected shared networks.

It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 56,347 bytes
File Type: Other
Memory Resident: Yes
Initial Samples Received Date: 26 Aug 2015
Payload: Connects to URLs/IPs, Compromises system security

Arrival Details

This worm arrives by connecting affected removable drives to a system.

It arrives by accessing affected shared networks.

Installation

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

  • C:\GoogleChrome\GoogleChrome.a3x

It drops the following component file(s):

  • C:\GoogleChrome\GoogleChrome.lnk
  • C:\GoogleChrome\GoogleUpdate.lnk
  • C:\GoogleChrome\MozillaFirefox.lnk
  • C:\GoogleChrome\My Music.lnk
  • C:\GoogleChrome\WindowsUpdate.lnk

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Google Chrome = "C:\GoogleChrome\WindowsUpdate.lnk"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
JavaUpdate = "C:\GoogleChrome\GoogleUpdate.lnk"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
NewJavaInstall = "C:\GoogleChrome\GoogleChrome.exe /AutoIt3ExecuteScript C:\GoogleChrome\GoogleChrome.a3x"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Google Chrome = "C:\GoogleChrome\WindowsUpdate.lnk"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
AdopeUpdate = "C:\GoogleChrome\GoogleUpdate.lnk"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
AdopeFlash = "C:\GoogleChrome\GoogleChrome.exe /AutoIt3ExecuteScript C:\GoogleChrome\GoogleChrome.a3x"

It enables its automatic execution at every system startup by dropping the following copies of itself into the Windows Common Startup folder:

  • {Common Startup}\Google Chrome.lnk
  • {Common Startup}\GoogleUpdate.lnk

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Environment
SEE_MASK_NOZONECHECKS = "1"

It modifies the following registry entries to hide files with Hidden attributes:

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

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

It creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
C:\GoogleChrome\GoogleChrome.exe = "C:\GoogleChrome\GoogleChrome.exe:*:Enabled:GoogleChrome.exe"

Backdoor Routine

This worm executes the following commands from a remote malicious user:

  • Execute remote arbitrary commands by executing cmd.exe
  • Download and execute arbitrary file - saved to %User Temp%
  • Uninstall itself

(Note: %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.)

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://{BLOCKED}d.info

It posts the following information to its command and control (C&C) server:

  • Propagation status
  • Computer Name
  • User Name
  • OS Version
  • OS Architecture
  • Anti-virus product installed

Other Details

This worm requires the following additional components to properly run:

  • {malware directory}:\GoogleChrome.exe - AutoIt script loader

NOTES:

Propagation Routine

It creates the following folders in all physical, removable, and network drives:

  • {drive letter}:\MozillaFirefox

It drops the following copies of itself in all physical, removable, and network drives:

  • {drive letter}:\MozillaFirefox\GoogleChrome.a3x

It drops the following component files all physical, removable, and network drives:

  • {drive letter}:\MozillaFirefox\GoogleChrome.exe - non-malicious AutoIt loader

It drops the following Shortcut (.LNK) files in all physical, removable, and network drives:

  • {drive letter}:\MozillaFirefox\GoogleChrome.lnk
  • {drive letter}:\MozillaFirefox\GoogleUpdate.lnk
  • {drive letter}:\MozillaFirefox\MozillaFirefox.lnk
  • {drive letter}:\MozillaFirefox\My Music.lnk
  • {drive letter}:\MozillaFirefox\WindowsUpdate.lnk
  • {drive letter}:\{1st-level subdirectory}\{1st-level subdirectory name}.lnk
  • {drive letter}:\{1st-level subdirectory}\My Music.lnk

The shorcut (.lnk) files are detected as LNK_MOZGOO.SM.

{Common Startup} is C:\Documents and Settings\All Users\Start Menu\Programs\Startup for Windows XP and older versions and C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup for Windows Vista and later OS versions.

  SOLUTION

Minimum Scan Engine: 9.750
VSAPI OPR PATTERN File: 11.882.01
VSAPI OPR PATTERN Date: 27 Aug 2015
OPP PATTERN File: 11.883.00
OPP PATTERN Date: 28 Aug 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

Remove malware/grayware files dropped/downloaded by WORM_MOZGOO.C. (Note: Please skip this step if the threats listed below have already been removed.)

    • LNK_MOZGOO.SM

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Google Chrome = "C:\GoogleChrome\WindowsUpdate.lnk"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • JavaUpdate = "C:\GoogleChrome\GoogleUpdate.lnk"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • NewJavaInstall = "C:\GoogleChrome\GoogleChrome.exe /AutoIt3ExecuteScript C:\GoogleChrome\GoogleChrome.a3x"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Google Chrome = "C:\GoogleChrome\WindowsUpdate.lnk"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • AdopeUpdate = "C:\GoogleChrome\GoogleUpdate.lnk"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • AdopeFlash = "C:\GoogleChrome\GoogleChrome.exe /AutoIt3ExecuteScript C:\GoogleChrome\GoogleChrome.a3x"
  • In HKEY_CURRENT_USER\Environment
    • SEE_MASK_NOZONECHECKS = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • C:\GoogleChrome\GoogleChrome.exe = "C:\GoogleChrome\GoogleChrome.exe:*:Enabled:GoogleChrome.exe"

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\Windows\CurrentVersion\Explorer\Advanced
    • From: ShowSuperHidden = "0"
      To: ShowSuperHidden = 1

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.
  • C:\GoogleChrome
  • {drive letter}:\MozillaFirefox

Step 8

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