BKDR_LUMINOSITY.G

October 07, 2016
 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

780,288 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

07 Oct 2016

Arrival Details

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

  • %User Temp%\HNGBFV\HNGBFV.exe

(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 creates the following folders:

  • %User Temp%\HNGBFV
  • %User Profile%\Application Data\Monitor
  • %Program Files%\Client
  • %User Profile%\Monitor\Logs
  • %User Profile%\Monitor\Files
  • %User Profile%\Monitor\Guard

(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.. %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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Other System Modifications

This backdoor deletes the following files:

  • %User Temp%\ Hostwin.exe
  • %User Temp%\HNGBFV\HNGBFV.exe:Zone.Identifier
  • %User Startup%\HNGBFV.exe:Zone.Identifier

(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.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo

It adds the following registry entries:

HKEY_CURRENT_USER\Software
6LXuQG8FKhFPjeIhCWIuQg== = "{random characters}"

HKEY_CURRENT_USER\Software
o8b0GNY/33zv/sH5yFmmtQ== = "GszhbkWQi8dUsDsAdJnQsw=="

HKEY_CURRENT_USER\Software
lbklMesEmyI0L2RJRWhb/w== = "7a9KbyM3wamnaRlSE0ETvXvo5apc7X3ZhDAOZ7d32Xg="

HKEY_CURRENT_USER\Software
o8b0GNY/33zv/sH5yFmmtQ== = "DLzsaUOkmKTqHxhy4HLZYg=="

HKEY_CURRENT_USER\Software
ijfI/WhLFHU1lQk1RHi4uQ== = "4axcIAAI6le4M97XDeChdg=="

HKEY_CURRENT_USER\Software
cIVZmIXXIoGws2F++nKxuUeUT23N0S/lWyXDZZ16OnA= = "mSJhLnzL83ED4qQU96i80w=="

HKEY_CURRENT_USER\Software
2IXgXysXrfO39mxXnHHTIJkiYS58y/NxA+KkFPeovNM= = "mSJhLnzL83ED4qQU96i80w=="

HKEY_CURRENT_USER\Software
215FhSdMd18qya/QVWB+QA== = "{random characters}"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "%User Temp%\HNGBFV\HNGBFV.exe"

Dropping Routine

This backdoor drops the following files:

  • %User Profile%\Guard\1

(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.)

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}.1.143
  • {BLOCKED}.141

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

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

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.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
    • msvideo

Step 3

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
    • 6LXuQG8FKhFPjeIhCWIuQg== = "{random characters}"
  • In HKEY_CURRENT_USER\Software
    • o8b0GNY/33zv/sH5yFmmtQ== = "GszhbkWQi8dUsDsAdJnQsw=="
  • In HKEY_CURRENT_USER\Software
    • lbklMesEmyI0L2RJRWhb/w== = "7a9KbyM3wamnaRlSE0ETvXvo5apc7X3ZhDAOZ7d32Xg="
  • In HKEY_CURRENT_USER\Software
    • o8b0GNY/33zv/sH5yFmmtQ== = "DLzsaUOkmKTqHxhy4HLZYg=="
  • In HKEY_CURRENT_USER\Software
    • ijfI/WhLFHU1lQk1RHi4uQ== = "4axcIAAI6le4M97XDeChdg=="
  • In HKEY_CURRENT_USER\Software
    • cIVZmIXXIoGws2F++nKxuUeUT23N0S/lWyXDZZ16OnA= = "mSJhLnzL83ED4qQU96i80w=="
  • In HKEY_CURRENT_USER\Software
    • 2IXgXysXrfO39mxXnHHTIJkiYS58y/NxA+KkFPeovNM= = "mSJhLnzL83ED4qQU96i80w=="
  • In HKEY_CURRENT_USER\Software
    • 215FhSdMd18qya/QVWB+QA== = "{random characters}"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • Load = "%User Temp%\HNGBFV\HNGBFV.exe"

Step 5

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.
  • %User Profile%\Guard\1

Step 6

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 Temp%\HNGBFV
  • %User Profile%\Application Data\Monitor
  • %Program Files%\Client
  • %User Profile%\Monitor\Logs
  • %User Profile%\Monitor\Files
  • %User Profile%\Monitor\Guard

Step 7

Scan your computer with your Trend Micro product to delete files detected as BKDR_LUMINOSITY.G. 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.

Step 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Temp%\ Hostwin.exe
  • %User Temp%\HNGBFV\HNGBFV.exe:Zone.Identifier
  • %User Startup%\HNGBFV.exe:Zone.Identifier


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