Analysis

  • max time kernel
    600s
  • max time network
    598s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240611-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240611-enlocale:en-usos:windows10-2004-x64system
  • submitted
    21/06/2024, 01:07

General

  • Target
    DCRatBuild.exe
  • Size 2.8MB
  • Sample240621-bgzzysycjn
  • SHA256 d07d79bfaecfaad730b473aedbedd0b1c49b5361f74aab3a79c7a37c623527eb
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Signatures

  • DcRat

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

  • Process spawned unexpected child process 15 IoCs

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

  • UAC bypass 3 TTPs 6 IoCs
  • DCRat payload 2 IoCs

    Detects payload of DCRat, commonly dropped by NSIS installers.

  • Disables Task Manager via registry modification
  • Checks computer location settings 2 TTPs 3 IoCs

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

  • Executes dropped EXE 4 IoCs
  • Reads user/profile data of web browsers 2 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

  • Checks whether UAC is enabled 1 TTPs 4 IoCs
  • Drops file in Program Files directory 5 IoCs
  • Drops file in Windows directory 2 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Modifies registry class 2 IoCs
  • Modifies registry key 1 TTPs 1 IoCs
  • Scheduled Task/Job: Scheduled Task 1 TTPs 15 IoCs

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

  • Suspicious behavior: EnumeratesProcesses 64 IoCs
  • Suspicious behavior: GetForegroundWindowSpam 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 4 IoCs
  • Suspicious use of WriteProcessMemory 17 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\DCRatBuild.exe
    "C:\Users\Admin\AppData\Local\Temp\DCRatBuild.exe"
    1⤵
    • Checks computer location settings
    • Modifies registry class
    • Suspicious use of WriteProcessMemory
    PID:624
    • C:\Windows\SysWOW64\WScript.exe
      "C:\Windows\System32\WScript.exe" "C:\PortFontMonitornetcommon\l8BmlyiJVw1zyyh.vbe"
      2⤵
      • Checks computer location settings
      • Suspicious use of WriteProcessMemory
      PID:4984
      • C:\Windows\SysWOW64\cmd.exe
        C:\Windows\system32\cmd.exe /c ""C:\PortFontMonitornetcommon\WdaIp4pfENVLh3Iemy6UjaXhu.bat" "
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:4656
        • C:\PortFontMonitornetcommon\BrokerSvc.exe
          "C:\PortFontMonitornetcommon\BrokerSvc.exe"
          4⤵
          • UAC bypass
          • Checks computer location settings
          • Executes dropped EXE
          • Checks whether UAC is enabled
          • Drops file in Program Files directory
          • Drops file in Windows directory
          • Modifies registry class
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          • Suspicious use of WriteProcessMemory
          • System policy modification
          PID:840
          • C:\Windows\System32\cmd.exe
            "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\w3ky7Mcri9.bat"
            5⤵
            • Suspicious use of WriteProcessMemory
            PID:4408
            • C:\Windows\system32\w32tm.exe
              w32tm /stripchart /computer:localhost /period:5 /dataonly /samples:2
              6⤵
                PID:3516
              • C:\PortFontMonitornetcommon\backgroundTaskHost.exe
                "C:\PortFontMonitornetcommon\backgroundTaskHost.exe"
                6⤵
                • UAC bypass
                • Executes dropped EXE
                • Checks whether UAC is enabled
                • Suspicious behavior: EnumeratesProcesses
                • Suspicious behavior: GetForegroundWindowSpam
                • Suspicious use of AdjustPrivilegeToken
                • System policy modification
                PID:1848
          • C:\Windows\SysWOW64\reg.exe
            reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /t REG_DWORD /d 1 /f
            4⤵
            • Modifies registry key
            PID:3320
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "SppExtComObjS" /sc MINUTE /mo 7 /tr "'C:\Program Files\Windows Sidebar\Gadgets\SppExtComObj.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:2044
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "SppExtComObj" /sc ONLOGON /tr "'C:\Program Files\Windows Sidebar\Gadgets\SppExtComObj.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:3852
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "SppExtComObjS" /sc MINUTE /mo 11 /tr "'C:\Program Files\Windows Sidebar\Gadgets\SppExtComObj.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:764
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "conhostc" /sc MINUTE /mo 8 /tr "'C:\Windows\Sun\Java\Deployment\conhost.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:1016
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "conhost" /sc ONLOGON /tr "'C:\Windows\Sun\Java\Deployment\conhost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:5096
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "conhostc" /sc MINUTE /mo 5 /tr "'C:\Windows\Sun\Java\Deployment\conhost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:1252
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 9 /tr "'C:\PortFontMonitornetcommon\backgroundTaskHost.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:4220
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHost" /sc ONLOGON /tr "'C:\PortFontMonitornetcommon\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:4892
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 10 /tr "'C:\PortFontMonitornetcommon\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:4092
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "taskhostwt" /sc MINUTE /mo 14 /tr "'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\taskhostw.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:548
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "taskhostw" /sc ONLOGON /tr "'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\taskhostw.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:4640
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "taskhostwt" /sc MINUTE /mo 7 /tr "'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\taskhostw.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:1884
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "TrustedInstallerT" /sc MINUTE /mo 13 /tr "'C:\Users\Public\Documents\My Videos\TrustedInstaller.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:3636
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "TrustedInstaller" /sc ONLOGON /tr "'C:\Users\Public\Documents\My Videos\TrustedInstaller.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:3788
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "TrustedInstallerT" /sc MINUTE /mo 10 /tr "'C:\Users\Public\Documents\My Videos\TrustedInstaller.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Scheduled Task/Job: Scheduled Task
      PID:5048
    • C:\Windows\System32\rundll32.exe
      C:\Windows\System32\rundll32.exe C:\Windows\System32\shell32.dll,SHCreateLocalServerRunDll {9aa46009-3ce0-458a-a354-715610a075e6} -Embedding
      1⤵
        PID:4472
      • C:\Windows\Sun\Java\Deployment\conhost.exe
        C:\Windows\Sun\Java\Deployment\conhost.exe
        1⤵
        • Executes dropped EXE
        • Suspicious use of AdjustPrivilegeToken
        PID:4072
      • C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\taskhostw.exe
        "C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\taskhostw.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of AdjustPrivilegeToken
        PID:3204

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

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            Downloads

            BrokerSvc.exe

            • Path C:\PortFontMonitornetcommon\BrokerSvc.exe
            • Size 2.5MB
            • SHA256 121d462ca9f33798e076d069ec6b84c5ae0573bbaac8df8dd78efbb7041bd30b
            • MD5 SHA1 SHA512 SSDEEP

            WdaIp4pfENVLh3Iemy6UjaXhu.bat

            • Path C:\PortFontMonitornetcommon\WdaIp4pfENVLh3Iemy6UjaXhu.bat
            • Size 166B
            • SHA256 949721b3bf385d01afc6b13e3c3ad7f37d87d29c49f243e2d59d4152925ee31b
            • MD5 SHA1 SHA512

            l8BmlyiJVw1zyyh.vbe

            • Path C:\PortFontMonitornetcommon\l8BmlyiJVw1zyyh.vbe
            • Size 237B
            • SHA256 8064029eab99ac1caed8414e03b5e7c981de56a6fcb7bdce3aa3b3438f430a2b
            • MD5 SHA1 SHA512

            w3ky7Mcri9.bat

            • Path C:\Users\Admin\AppData\Local\Temp\w3ky7Mcri9.bat
            • Size 215B
            • SHA256 6dea0dd9907223d82c52957047978c15fa5df167aafccd0b9c057fd2043e3b5a
            • MD5 SHA1 SHA512

            memory/840-19-0x000000001BD80000-0x000000001BDD6000-memory.dmp

            memory/840-22-0x000000001BD20000-0x000000001BD2C000-memory.dmp

            memory/840-15-0x000000001B7B0000-0x000000001B7CC000-memory.dmp

            memory/840-16-0x000000001BD30000-0x000000001BD80000-memory.dmp

            memory/840-18-0x000000001BCF0000-0x000000001BCFA000-memory.dmp

            memory/840-17-0x000000001BCE0000-0x000000001BCE8000-memory.dmp

            memory/840-13-0x0000000000920000-0x0000000000B9A000-memory.dmp

            memory/840-20-0x000000001BD00000-0x000000001BD0C000-memory.dmp

            memory/840-21-0x000000001BD10000-0x000000001BD18000-memory.dmp

            memory/840-14-0x000000001B7A0000-0x000000001B7AE000-memory.dmp

            memory/840-23-0x000000001BDD0000-0x000000001BDDC000-memory.dmp

            memory/840-24-0x000000001C150000-0x000000001C15C000-memory.dmp

            memory/840-25-0x000000001BFE0000-0x000000001BFEE000-memory.dmp

            memory/840-26-0x000000001BFF0000-0x000000001BFFC000-memory.dmp

            memory/840-27-0x000000001C000000-0x000000001C00C000-memory.dmp

            memory/840-12-0x00007FF8D8EC3000-0x00007FF8D8EC5000-memory.dmp

            memory/1848-47-0x000000001C200000-0x000000001C256000-memory.dmp

            memory/1848-48-0x000000001D370000-0x000000001D532000-memory.dmp