ALIASES:

Backdoor:Win32/NinjaSpy.C (Microsoft); PWS-Banker.gen.b (McAfee); Backdoor.Trojan (Symantec); Backdoor.Win32.NinjaSpy.c (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse BackDoor.Generic.AJC (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 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.

  TECHNICAL DETAILS

File Size: 823,298 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 17 Apr 2013

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:

  • %Windows%\cmd.dll

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Windows = "%Windows%\cmd.dll"

Other System Modifications

This backdoor deletes the following files:

  • %Windows%\Recent\Explorer.dll.lnk
  • %Windows%\Recent\Kernel32.ocx.lnk
  • %Windows%\Recent\Regedit.ocx.lnk

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

It adds the following registry keys:

HKEY_CLASSES_ROOT\dllfile\shell\
open\command

HKEY_CLASSES_ROOT\sysfile\shell\
open\command

HKEY_CLASSES_ROOT\ocxfile\shell\
open\command

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "cmd.dll"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = "2a425e19"

(Note: The default value data of the said registry entry is 41107b81.)

Dropping Routine

This backdoor drops the following files:

  • %System%\Explorer.dll
  • %System%\Kernel32.ocx
  • %Windows%\Regedit.ocx

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

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

Restart in Safe Mode

[ Learn More ]

Step 3

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_CLASSES_ROOT\dllfile\shell\open
    • command
  • In HKEY_CLASSES_ROOT\sysfile\shell\open
    • command
  • In HKEY_CLASSES_ROOT\ocxfile\shell\open
    • command

Step 4

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
    • Microsoft Windows = "%Windows%\cmd.dll"

Step 5

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_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: Name = "cmd.dll"
      To: Name = ""iexplore.exe""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: ID = "2a425e19"
      To: ID = ""41107b81""

Step 6

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %System%\Explorer.dll
  • %System%\Kernel32.ocx
  • %Windows%\Regedit.ocx

Step 7

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

  • %Windows%\Recent\Explorer.dll.lnk
  • %Windows%\Recent\Kernel32.ocx.lnk
  • %Windows%\Recent\Regedit.ocx.lnk


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