Analysis

  • max time kernel
    150s
  • max time network
    148s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240426-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240426-enlocale:en-usos:windows10-2004-x64system
  • submitted
    22/05/2024, 14:27

General

  • Target
    Build.exe
  • Size 1.1MB
  • Sample240522-rsfcpaed3y
  • SHA256 1c33d65d9936c4c4db8a996c65d24d547ccec4a05f6f144673818946aa49e9d2
  • MD5 SHA1 SHA512 SSDEEP
Score
10/10

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 30 IoCs

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

  • DCRat payload 2 IoCs

    Detects payload of DCRat, commonly dropped by NSIS installers.

  • Checks computer location settings 2 TTPs 3 IoCs

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

  • Executes dropped EXE 2 IoCs
  • Legitimate hosting services abused for malware hosting/C2 1 TTPs 2 IoCs
  • Drops file in Program Files directory 2 IoCs
  • Drops file in Windows directory 2 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Creates scheduled task(s) 1 TTPs 30 IoCs

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

  • Modifies registry class 2 IoCs
  • Suspicious behavior: EnumeratesProcesses 14 IoCs
  • Suspicious behavior: GetForegroundWindowSpam 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 14 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\Build.exe
    "C:\Users\Admin\AppData\Local\Temp\Build.exe"
    1⤵
    • Checks computer location settings
    • Modifies registry class
    • Suspicious use of WriteProcessMemory
    PID:3780
    • C:\Windows\SysWOW64\WScript.exe
      "C:\Windows\System32\WScript.exe" "C:\mssurrogate\MCh88oSE20.vbe"
      2⤵
      • Checks computer location settings
      • Suspicious use of WriteProcessMemory
      PID:4880
      • C:\Windows\SysWOW64\cmd.exe
        C:\Windows\system32\cmd.exe /c ""C:\mssurrogate\W0CHjezgOi5W2.bat" "
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:5024
        • C:\mssurrogate\surrogateServer.exe
          "C:\mssurrogate\surrogateServer.exe"
          4⤵
          • Checks computer location settings
          • Executes dropped EXE
          • 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
          PID:3628
          • C:\Windows\System32\cmd.exe
            "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\78qztKSG7x.bat"
            5⤵
            • Suspicious use of WriteProcessMemory
            PID:3028
            • C:\Windows\system32\w32tm.exe
              w32tm /stripchart /computer:localhost /period:5 /dataonly /samples:2
              6⤵
                PID:1096
              • C:\Recovery\WindowsRE\backgroundTaskHost.exe
                "C:\Recovery\WindowsRE\backgroundTaskHost.exe"
                6⤵
                • Executes dropped EXE
                • Suspicious behavior: EnumeratesProcesses
                • Suspicious behavior: GetForegroundWindowSpam
                • Suspicious use of AdjustPrivilegeToken
                PID:3196
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 8 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1540
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1676
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 14 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:688
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 5 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:780
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4080
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 14 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4932
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "TextInputHostT" /sc MINUTE /mo 9 /tr "'C:\Recovery\WindowsRE\TextInputHost.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:2964
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "TextInputHost" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\TextInputHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:3964
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "TextInputHostT" /sc MINUTE /mo 9 /tr "'C:\Recovery\WindowsRE\TextInputHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:3752
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 10 /tr "'C:\Users\Default\Start Menu\backgroundTaskHost.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:3496
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHost" /sc ONLOGON /tr "'C:\Users\Default\Start Menu\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1708
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 11 /tr "'C:\Users\Default\Start Menu\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:2612
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 8 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:224
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4412
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 13 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:3852
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 6 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4508
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1492
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 5 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1140
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "lsassl" /sc MINUTE /mo 7 /tr "'C:\Windows\TAPI\lsass.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1420
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "lsass" /sc ONLOGON /tr "'C:\Windows\TAPI\lsass.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4068
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "lsassl" /sc MINUTE /mo 13 /tr "'C:\Windows\TAPI\lsass.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:2912
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 11 /tr "'C:\Recovery\WindowsRE\backgroundTaskHost.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:2068
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHost" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1916
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 9 /tr "'C:\Recovery\WindowsRE\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4384
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 11 /tr "'C:\Users\Public\Downloads\backgroundTaskHost.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4476
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHost" /sc ONLOGON /tr "'C:\Users\Public\Downloads\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:684
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 8 /tr "'C:\Users\Public\Downloads\backgroundTaskHost.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:2388
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "cmdc" /sc MINUTE /mo 7 /tr "'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.0\de\cmd.exe'" /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:4212
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "cmd" /sc ONLOGON /tr "'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.0\de\cmd.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1216
    • C:\Windows\system32\schtasks.exe
      schtasks.exe /create /tn "cmdc" /sc MINUTE /mo 5 /tr "'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.0\de\cmd.exe'" /rl HIGHEST /f
      1⤵
      • Process spawned unexpected child process
      • Creates scheduled task(s)
      PID:1236

    Network

          MITRE ATT&CK Enterprise v15

          Replay Monitor

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          Downloads

          78qztKSG7x.bat

          • Path C:\Users\Admin\AppData\Local\Temp\78qztKSG7x.bat
          • Size 209B
          • SHA256 d4aa3412984ca901dfdec175ac240146d012003f436c9b106a1df17039599eea
          • MD5 SHA1 SHA512

          MCh88oSE20.vbe

          • Path C:\mssurrogate\MCh88oSE20.vbe
          • Size 201B
          • SHA256 0854c211911d16745331faf54d5d2807cb6e32c1da42af636741c422d7432065
          • MD5 SHA1 SHA512

          W0CHjezgOi5W2.bat

          • Path C:\mssurrogate\W0CHjezgOi5W2.bat
          • Size 36B
          • SHA256 ac3847b4739f5c90c1939eb0b01d47ba8cc6646bcf99f3046bb988c803707790
          • MD5 SHA1 SHA512

          surrogateServer.exe

          • Path C:\mssurrogate\surrogateServer.exe
          • Size 830KB
          • SHA256 5ba64e0a47fb63fb4694c0bc887dd544645adae69dd6bb8e1128bc61ed7d8148
          • MD5 SHA1 SHA512 SSDEEP

          memory/3628-12-0x00007FFF9DBC3000-0x00007FFF9DBC5000-memory.dmp

          memory/3628-13-0x0000000000A10000-0x0000000000AE6000-memory.dmp