Analysis

  • max time kernel
    1798s
  • max time network
    1800s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240508-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240508-enlocale:en-usos:windows10-2004-x64system
  • submitted
    26/05/2024, 15:57

General

  • Target
    DarkLoader.exe
  • Size 1.4MB
  • Sample240526-teaamabh4y
  • SHA256 e717a0bd95ad8f0798d01d6cf0f10dcd18b162554d9555338a73b52a1db3e404
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Signatures

  • DcRat

    DarkCrystal(DC) is a new .NET RAT active since June 2019 capable of loading additional plugins.

  • Modifies WinLogon for persistence 2 TTPs 3 IoCs
  • Process spawned unexpected child process 9 IoCs

    This typically indicates the parent process was compromised via an exploit or macro.

  • UAC bypass 3 TTPs 6 IoCs
  • DCRat payload 3 IoCs

    Detects payload of DCRat, commonly dropped by NSIS installers.

  • Checks computer location settings 2 TTPs 5 IoCs

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

  • Executes dropped EXE 14 IoCs
  • Adds Run key to start application 2 TTPs 6 IoCs
  • Checks whether UAC is enabled 1 TTPs 4 IoCs
  • Looks up external IP address via web service 1 IoCs

    Uses a legitimate IP lookup service to find the infected system's external IP.

  • Drops file in Program Files directory 5 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Creates scheduled task(s) 1 TTPs 9 IoCs

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

  • Modifies registry class 2 IoCs
  • Suspicious behavior: EnumeratesProcesses 16 IoCs
  • Suspicious behavior: GetForegroundWindowSpam 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 13 IoCs
  • Suspicious use of SetWindowsHookEx 1 IoCs
  • Suspicious use of WriteProcessMemory 21 IoCs
  • System policy modification 1 TTPs 6 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:\Users\Admin\AppData\Local\Temp\DarkLoader.exe
    "C:\Users\Admin\AppData\Local\Temp\DarkLoader.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:228
    • C:\Users\Admin\AppData\Local\Temp\RarSFX0\DarkPatcher.exe
      "C:\Users\Admin\AppData\Local\Temp\RarSFX0\DarkPatcher.exe"
      2⤵
      • Checks computer location settings
      • Executes dropped EXE
      • Modifies registry class
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:3620
      • C:\Windows\SysWOW64\WScript.exe
        "C:\Windows\System32\WScript.exe" "C:\webruntimehost\uzRhfXiJ08p4ubq.vbe"
        3⤵
        • Checks computer location settings
        • Suspicious use of WriteProcessMemory
        PID:1132
        • C:\Windows\SysWOW64\cmd.exe
          C:\Windows\system32\cmd.exe /c ""C:\webruntimehost\xQ9PE.bat" "
          4⤵
          • Suspicious use of WriteProcessMemory
          PID:2912
          • C:\webruntimehost\bridgeBlockdhcp.exe
            "C:\webruntimehost\bridgeBlockdhcp.exe"
            5⤵
            • Modifies WinLogon for persistence
            • UAC bypass
            • Checks computer location settings
            • Executes dropped EXE
            • Adds Run key to start application
            • Checks whether UAC is enabled
            • Drops file in Program Files directory
            • Suspicious behavior: EnumeratesProcesses
            • Suspicious use of AdjustPrivilegeToken
            • Suspicious use of WriteProcessMemory
            • System policy modification
            PID:3084
            • C:\Program Files\Windows Mail\WaaSMedicAgent.exe
              "C:\Program Files\Windows Mail\WaaSMedicAgent.exe"
              6⤵
              • UAC bypass
              • Checks computer location settings
              • Executes dropped EXE
              • Checks whether UAC is enabled
              • Modifies registry class
              • Suspicious behavior: EnumeratesProcesses
              • Suspicious behavior: GetForegroundWindowSpam
              • Suspicious use of AdjustPrivilegeToken
              • Suspicious use of WriteProcessMemory
              • System policy modification
              PID:4268
              • C:\Windows\System32\WScript.exe
                "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\8a6b8683-2d36-4e5d-9f7a-ed8ec6cface8.vbs"
                7⤵
                  PID:4840
                • C:\Windows\System32\WScript.exe
                  "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\1a7924cd-d6cf-49eb-8482-4d7ef09d9f04.vbs"
                  7⤵
                    PID:2432
        • C:\Windows\system32\cmd.exe
          C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\RarSFX0\Loader.bat" "
          2⤵
          • Suspicious use of WriteProcessMemory
          PID:3088
          • C:\Windows\system32\chcp.com
            chcp 65001
            3⤵
              PID:1528
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "WaaSMedicAgentW" /sc MINUTE /mo 9 /tr "'C:\Program Files\Windows Mail\WaaSMedicAgent.exe'" /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:4948
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "WaaSMedicAgent" /sc ONLOGON /tr "'C:\Program Files\Windows Mail\WaaSMedicAgent.exe'" /rl HIGHEST /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:4400
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "WaaSMedicAgentW" /sc MINUTE /mo 14 /tr "'C:\Program Files\Windows Mail\WaaSMedicAgent.exe'" /rl HIGHEST /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:4408
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "conhostc" /sc MINUTE /mo 10 /tr "'C:\webruntimehost\conhost.exe'" /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:3912
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "conhost" /sc ONLOGON /tr "'C:\webruntimehost\conhost.exe'" /rl HIGHEST /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:4724
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "conhostc" /sc MINUTE /mo 5 /tr "'C:\webruntimehost\conhost.exe'" /rl HIGHEST /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:4296
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "TrustedInstallerT" /sc MINUTE /mo 14 /tr "'C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe'" /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:872
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "TrustedInstaller" /sc ONLOGON /tr "'C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe'" /rl HIGHEST /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:4212
        • C:\Windows\system32\schtasks.exe
          schtasks.exe /create /tn "TrustedInstallerT" /sc MINUTE /mo 10 /tr "'C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe'" /rl HIGHEST /f
          1⤵
          • Process spawned unexpected child process
          • Creates scheduled task(s)
          PID:2532
        • C:\webruntimehost\conhost.exe
          C:\webruntimehost\conhost.exe
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:5112
        • C:\webruntimehost\conhost.exe
          C:\webruntimehost\conhost.exe
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:1164
        • C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe
          "C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe"
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:404
        • C:\Program Files\Windows Mail\WaaSMedicAgent.exe
          "C:\Program Files\Windows Mail\WaaSMedicAgent.exe"
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:436
        • C:\webruntimehost\conhost.exe
          C:\webruntimehost\conhost.exe
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:2396
        • C:\webruntimehost\conhost.exe
          C:\webruntimehost\conhost.exe
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:4284
        • C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe
          "C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe"
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:4852
        • C:\webruntimehost\conhost.exe
          C:\webruntimehost\conhost.exe
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:1224
        • C:\Program Files\Windows Mail\WaaSMedicAgent.exe
          "C:\Program Files\Windows Mail\WaaSMedicAgent.exe"
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:2828
        • C:\webruntimehost\conhost.exe
          C:\webruntimehost\conhost.exe
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:3620
        • C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe
          "C:\Program Files\Microsoft Office 15\ClientX64\TrustedInstaller.exe"
          1⤵
          • Executes dropped EXE
          • Suspicious use of AdjustPrivilegeToken
          PID:4380

        Network

              MITRE ATT&CK Enterprise v15

              Replay Monitor

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              Downloads

              conhost.exe.log

              • Path C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\conhost.exe.log
              • Size 1KB
              • SHA256 ee954c5d8156fd8890e582c716e5758ed9b33721258f10e758bdc31ccbcb1924
              • MD5 SHA1 SHA512

              1a7924cd-d6cf-49eb-8482-4d7ef09d9f04.vbs

              • Path C:\Users\Admin\AppData\Local\Temp\1a7924cd-d6cf-49eb-8482-4d7ef09d9f04.vbs
              • Size 500B
              • SHA256 aaa9f685cd7057a124abe4a38628228cce4de972e90aa0ffd4611f39a1dd5295
              • MD5 SHA1 SHA512

              8a6b8683-2d36-4e5d-9f7a-ed8ec6cface8.vbs

              • Path C:\Users\Admin\AppData\Local\Temp\8a6b8683-2d36-4e5d-9f7a-ed8ec6cface8.vbs
              • Size 724B
              • SHA256 6c18936c596cd5a0c0925e6fa407b1a94760926576ff056dbdb3edd6ac4c8245
              • MD5 SHA1 SHA512

              DarkPatcher.exe

              • Path C:\Users\Admin\AppData\Local\Temp\RarSFX0\DarkPatcher.exe
              • Size 1.8MB
              • SHA256 f9b1beddd0d4f8f58a8c4a83b7f9543c49991722bf6fdf87e41e8122ebf3951a
              • MD5 SHA1 SHA512 SSDEEP

              Loader.bat

              • Path C:\Users\Admin\AppData\Local\Temp\RarSFX0\Loader.bat
              • Size 665B
              • SHA256 db26bf2b4b50d48e760d2bd8d75b5d0249d8edd2b909a05dff6d69abf1b43a34
              • MD5 SHA1 SHA512

              bridgeBlockdhcp.exe

              • Path C:\webruntimehost\bridgeBlockdhcp.exe
              • Size 1.3MB
              • SHA256 979e9c0fbc3e74ea555cfa6c0f1ba262fa3b0641e91be3aca4e89ba7eb69da97
              • MD5 SHA1 SHA512 SSDEEP

              uzRhfXiJ08p4ubq.vbe

              • Path C:\webruntimehost\uzRhfXiJ08p4ubq.vbe
              • Size 197B
              • SHA256 69687c36f9e9c8674c379d72490eec8a74ae586ed3dc9f0b97490f90bb9d7013
              • MD5 SHA1 SHA512

              xQ9PE.bat

              • Path C:\webruntimehost\xQ9PE.bat
              • Size 39B
              • SHA256 ad7a789712a9c7ff89c73fc8a7a5e9f3f7c8e8ccb0bbe33b8421b8c0d24b48aa
              • MD5 SHA1 SHA512

              memory/3084-29-0x000000001BAB0000-0x000000001BAC6000-memory.dmp

              memory/3084-30-0x000000001BAD0000-0x000000001BADA000-memory.dmp

              memory/3084-31-0x000000001BAE0000-0x000000001BAEC000-memory.dmp

              memory/3084-32-0x000000001BAF0000-0x000000001BAFA000-memory.dmp

              memory/3084-33-0x000000001C010000-0x000000001C01E000-memory.dmp

              memory/3084-34-0x000000001C6D0000-0x000000001C6DC000-memory.dmp

              memory/3084-28-0x000000001BAA0000-0x000000001BAA8000-memory.dmp

              memory/3084-27-0x0000000001540000-0x000000000154E000-memory.dmp

              memory/3084-26-0x0000000000D20000-0x0000000000E68000-memory.dmp