Analysis by: Paulo Samson
ALIASES:

Trojan.Win32.Shadowpad (IKARUS)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

  TECHNICAL DETAILS

File Size: 123904 bytes
File Type: DLL
Initial Samples Received Date: 27 Jul 2020
Payload: Connects to URLs/IPs, Drops files, Modifies system registry

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 adds the following folders:

  • %All Users Profile%\PlugIns

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

It drops the following files:

  • %All Users Profile%\PlugIns\plugin.exe --> copy of %System%\rundll32.exe
  • %All Users Profile%\PlugIns\TosBtKbd.dll

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It adds the following processes:

  • %All Users Profile%\PlugIns\plugin.exe
  • %System%\svchost.exe

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). . %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It injects codes into the following process(es):

  • %System%\svchost.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

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
PlugIns = %All Users Profile%\PlugIns\plugin.exe

It starts the following services:

  • Service Name: PlugIns
    Display Name: PlugIns
    Description: The service is responsible for applying settings configured.
    Startup Type: Automatic
    Path to executable: %All UsersProfile%\PlugIns\plugin.exe

Other System Modifications

This Backdoor adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\UBV
UBV = { Hex Values }

Backdoor Routine

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

  • Receive arbitrary codes

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

  • http://{BLOCKED}.{BLOCKED}.224.29:{different ports}

Other Details

This Backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\UBV

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
MDDND

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.120.07
FIRST VSAPI PATTERN DATE: 23 Jul 2020
VSAPI OPR PATTERN File: 16.121.00
VSAPI OPR PATTERN Date: 24 Jul 2020

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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

Disable this malware service

[ Learn More ]
  •  
    • PlugIns

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
    • PlugIns = %All Users Profile%\PlugIns\plugin.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\UBV
    • UBV = { Hex Values }

Step 6

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\SOFTWARE\UBV
    • "" = ""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MDDND
    • "" = ""

Step 7

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.
  • %All Users Profile%\PlugIns\plugin.exe
  • %All Users Profile%\PlugIns\TosBtKbd.dll

Step 8

Search and delete this folder

[ 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.
  • %All Users Profile%\PlugIns

Step 9

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.SHADOWPAD.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.


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