Analysis

  • max time kernel
    150s
  • max time network
    184s
  • platform
    windows7_x64
  • resource
    win7v20210408
  • submitted
    04/07/2021, 06:55

General

  • Target
    b0da133665a2d0af6ac00040b1e872ce.exe
  • Size 823KB
  • Sample210704-hrvec5r41e
  • SHA256 eb55fdd4d15cf3d07905037073a275ba2697e8fdb2a9f60c0b16cf70969cd476
  • MD5 SHA1 SHA512

Malware Config

Extracted

Family
  • remcos

Version
  • 3.1.5 Pro

Botnet
  • chrome

C2
  • fieldsdegreenf.duckdns.org:6553

  • aaeeerbbbeee.duckdns.org:6553

  • sdegreenfieldsdeeenf.duckdns.org:6553

Attributes
  • audio_folder

    MicRecords

  • audio_path

    %AppData%

  • 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

    true

  • install_path

    %AppData%

  • keylog_crypt

    false

  • keylog_file

    logs.dat

  • keylog_flag

    false

  • keylog_folder

    remcos

  • keylog_path

    %AppData%

  • mouse_option

    false

  • mutex

    Remcos-09G4NK

  • screenshot_crypt

    false

  • screenshot_flag

    false

  • screenshot_folder

    Screenshots

  • screenshot_path

    %AppData%

  • screenshot_time

    10

  • startup_value

    Remcos

  • take_screenshot_option

    false

  • take_screenshot_time

    5

  • take_screenshot_title

    notepad;solitaire;

Signatures

  • Remcos

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

  • Executes dropped EXE 2 IoCs
  • Loads dropped DLL 1 IoCs
  • Adds Run key to start application 2 TTPs 4 IoCs
  • Suspicious use of SetThreadContext 5 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Modifies Internet Explorer settings 1 TTPs 53 IoCs
  • Suspicious use of FindShellTrayWindow 1 IoCs
  • Suspicious use of SetWindowsHookEx 9 IoCs
  • Suspicious use of WriteProcessMemory 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\b0da133665a2d0af6ac00040b1e872ce.exe
    "C:\Users\Admin\AppData\Local\Temp\b0da133665a2d0af6ac00040b1e872ce.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:1644
    • C:\Users\Admin\AppData\Local\Temp\b0da133665a2d0af6ac00040b1e872ce.exe
      "{path}"
      2⤵
      • Adds Run key to start application
      • Suspicious use of WriteProcessMemory
      PID:1288
      • C:\Windows\SysWOW64\WScript.exe
        "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\install.vbs"
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:1524
        • C:\Windows\SysWOW64\cmd.exe
          "C:\Windows\System32\cmd.exe" /c "C:\Users\Admin\AppData\Roaming\Remcos\remcos.exe"
          4⤵
          • Loads dropped DLL
          • Suspicious use of WriteProcessMemory
          PID:744
          • C:\Users\Admin\AppData\Roaming\Remcos\remcos.exe
            C:\Users\Admin\AppData\Roaming\Remcos\remcos.exe
            5⤵
            • Executes dropped EXE
            • Suspicious use of SetThreadContext
            • Suspicious use of WriteProcessMemory
            PID:1668
            • C:\Users\Admin\AppData\Roaming\Remcos\remcos.exe
              "{path}"
              6⤵
              • Executes dropped EXE
              • Adds Run key to start application
              • Suspicious use of SetThreadContext
              • Suspicious use of SetWindowsHookEx
              • Suspicious use of WriteProcessMemory
              PID:1144
              • C:\Windows\SysWOW64\svchost.exe
                C:\Windows\SysWOW64\svchost.exe
                7⤵
                • Suspicious use of WriteProcessMemory
                PID:1376
                • C:\Program Files\Internet Explorer\iexplore.exe
                  "C:\Program Files\Internet Explorer\iexplore.exe" http://go.microsoft.com/fwlink/?prd=11324&pver=4.5&sbp=AppLaunch2&plcid=0x409&o1=SHIM_NOVERSION_FOUND&version=(null)&processName=svchost.exe&platform=0009&osver=5&isServer=0&shimver=4.0.30319.0
                  8⤵
                  • Modifies Internet Explorer settings
                  • Suspicious use of FindShellTrayWindow
                  • Suspicious use of SetWindowsHookEx
                  • Suspicious use of WriteProcessMemory
                  PID:280
                  • C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE
                    "C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE" SCODEF:280 CREDAT:275457 /prefetch:2
                    9⤵
                    • Modifies Internet Explorer settings
                    • Suspicious use of SetWindowsHookEx
                    PID:1300
                  • C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE
                    "C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE" SCODEF:280 CREDAT:603143 /prefetch:2
                    9⤵
                    • Modifies Internet Explorer settings
                    • Suspicious use of SetWindowsHookEx
                    PID:856
              • C:\Windows\SysWOW64\svchost.exe
                C:\Windows\SysWOW64\svchost.exe
                7⤵
                  PID:988
                • C:\Windows\SysWOW64\svchost.exe
                  C:\Windows\SysWOW64\svchost.exe
                  7⤵
                    PID:524

      Network

            MITRE ATT&CK Enterprise v6

            Replay Monitor

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            Downloads

            memory/280-94-0x000007FEFB561000-0x000007FEFB563000-memory.dmp

            memory/1144-89-0x0000000000400000-0x0000000000479000-memory.dmp

            memory/1288-65-0x0000000000400000-0x0000000000479000-memory.dmp

            memory/1288-68-0x0000000000400000-0x0000000000479000-memory.dmp

            memory/1288-67-0x0000000075041000-0x0000000075043000-memory.dmp

            memory/1376-87-0x0000000000400000-0x00000000004D4000-memory.dmp

            memory/1644-59-0x0000000000BF0000-0x0000000000BF1000-memory.dmp

            memory/1644-64-0x0000000008310000-0x00000000083A6000-memory.dmp

            memory/1644-63-0x0000000008240000-0x000000000830C000-memory.dmp

            memory/1644-62-0x00000000003C0000-0x00000000003C2000-memory.dmp

            memory/1644-61-0x0000000004D00000-0x0000000004D01000-memory.dmp

            memory/1668-77-0x0000000000A60000-0x0000000000A61000-memory.dmp

            memory/1668-79-0x0000000000950000-0x0000000000951000-memory.dmp