Analysis

  • max time kernel
    148s
  • max time network
    152s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240426-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240426-enlocale:en-usos:windows10-2004-x64system
  • submitted
    10/05/2024, 01:24

General

  • Target
    Tax Organizer 2023/g2m.dll
  • Size 25.9MB
  • Sample240510-bssd9aaf5s
  • SHA256 2643dbabde4595b6505a2c5f74810022a75322cb1c0a7a889783ad794f55df7d
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • remcos

Botnet
  • RemoteHost

C2
  • faststaynow.duckdns.org:5057

Attributes
  • audio_folder

    MicRecords

  • audio_record_time

    5

  • connect_delay

    0

  • connect_interval

    1

  • copy_file

    remcos.exe

  • copy_folder

    Remcos

  • delete_file

    false

  • hide_file

    false

  • hide_keylog_file

    false

  • install_flag

    false

  • keylog_crypt

    false

  • keylog_file

    logs.dat

  • keylog_flag

    false

  • keylog_folder

    remcos

  • mouse_option

    false

  • mutex

    Rmc-DRFJJD

  • screenshot_crypt

    false

  • screenshot_flag

    false

  • screenshot_folder

    Screenshots

  • screenshot_path

    %AppData%

  • screenshot_time

    10

  • take_screenshot_option

    false

  • take_screenshot_time

    5

Signatures

  • Remcos

    Remcos is a closed-source remote control and surveillance software.

  • Blocklisted process makes network request 3 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Adds Run key to start application 2 TTPs 1 IoCs
  • Suspicious use of NtCreateThreadExHideFromDebugger 1 IoCs
  • Command and Scripting Interpreter: PowerShell 1 TTPs 1 IoCs

    Using powershell.exe command.

  • Enumerates physical storage devices 1 TTPs

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

  • Modifies registry class 1 IoCs
  • Suspicious behavior: EnumeratesProcesses 2 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 24 IoCs

Processes

  • C:\Windows\system32\regsvr32.exe
    regsvr32 /s "C:\Users\Admin\AppData\Local\Temp\Tax Organizer 2023\g2m.dll"
    1⤵
    • Suspicious use of WriteProcessMemory
    PID:1548
    • C:\Windows\SysWOW64\regsvr32.exe
      /s "C:\Users\Admin\AppData\Local\Temp\Tax Organizer 2023\g2m.dll"
      2⤵
      • Suspicious use of NtCreateThreadExHideFromDebugger
      • Suspicious use of WriteProcessMemory
      PID:4304
      • C:\Windows\SysWOW64\regsvr32.exe
        "C:\Windows\SysWOW64\regsvr32.exe"
        3⤵
        • Modifies registry class
        • Suspicious use of WriteProcessMemory
        PID:1820
        • C:\Windows\SysWOW64\WScript.exe
          "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\Memory.vbs"
          4⤵
          • Blocklisted process makes network request
          • Checks computer location settings
          • Suspicious use of WriteProcessMemory
          PID:2964
          • C:\Windows\SysWOW64\cmd.exe
            C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Roaming\WindowsServices\VJQSJ.cmd" "
            5⤵
            • Suspicious use of WriteProcessMemory
            PID:1368
            • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
              PowerShell.exe -NoProfile -ExecutionPolicy Bypass -Command C:\Users\Admin\AppData\Roaming\WindowsServices\FNOBH.ps1
              6⤵
              • Command and Scripting Interpreter: PowerShell
              • Suspicious behavior: EnumeratesProcesses
              • Suspicious use of AdjustPrivilegeToken
              PID:816
      • C:\Windows\SysWOW64\cmd.exe
        cmd.exe /C reg add "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "*Chrome" /t REG_SZ /d "rundll32.exe C:\Users\Admin\AppData\Roaming\HEARTB.dll",EntryPoint /f & exit
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:2016
        • C:\Windows\SysWOW64\reg.exe
          reg add "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "*Chrome" /t REG_SZ /d "rundll32.exe C:\Users\Admin\AppData\Roaming\HEARTB.dll",EntryPoint /f
          4⤵
          • Adds Run key to start application
          PID:2884

Network

        MITRE ATT&CK Enterprise v15

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        Memory.vbs

        • Path C:\Users\Admin\AppData\Local\Temp\Memory.vbs
        • Size 6.8MB
        • SHA256 f90c2ec81fb78e657dc3d359bcf59a557d56ddc8e1b33e9b205707a221e21f36
        • MD5 SHA1 SHA512 SSDEEP

        __PSScriptPolicyTest_14x4omgm.tqx.ps1

        • Path C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_14x4omgm.tqx.ps1
        • Size 60B
        • SHA256 96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7
        • MD5 SHA1 SHA512

        FDNUA.vbs

        • Path C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\FDNUA.vbs
        • Size 276B
        • SHA256 5819dd543e8a14f37c805762dcd5a5d29d7dad9ff8c16041605576cab4fb2fd0
        • MD5 SHA1 SHA512

        VJQSJ.cmd

        • Path C:\Users\Admin\AppData\Roaming\WindowsServices\VJQSJ.cmd
        • Size 75B
        • SHA256 b05c782898be147fc51e30f958325cf4d0494a46ee37ae8bbe52d47202aa792e
        • MD5 SHA1 SHA512

        memory/816-67-0x0000000005D20000-0x0000000005D6C000-memory.dmp

        memory/816-66-0x0000000005C90000-0x0000000005CAE000-memory.dmp

        memory/816-65-0x00000000056A0000-0x00000000059F4000-memory.dmp

        memory/816-55-0x0000000005630000-0x0000000005696000-memory.dmp

        memory/816-54-0x00000000054D0000-0x0000000005536000-memory.dmp

        memory/816-53-0x0000000004DF0000-0x0000000004E12000-memory.dmp

        memory/816-52-0x0000000004EA0000-0x00000000054C8000-memory.dmp

        memory/816-51-0x00000000026D0000-0x0000000002706000-memory.dmp

        memory/1820-11-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-8-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-18-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-15-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-23-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-24-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-25-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-14-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-13-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-77-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-76-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-72-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-2-0x0000000000F60000-0x0000000000F61000-memory.dmp

        memory/1820-10-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-5-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-6-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-16-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-71-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/1820-70-0x0000000000ED0000-0x0000000000F52000-memory.dmp

        memory/4304-0-0x0000000010000000-0x0000000011A85000-memory.dmp

        memory/4304-4-0x0000000010000000-0x0000000011A85000-memory.dmp

        memory/4304-1-0x0000000010B6A000-0x0000000010B84000-memory.dmp

        memory/4304-12-0x0000000010000000-0x0000000011A85000-memory.dmp