Analysis

  • max time kernel
    135s
  • max time network
    153s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20241007-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20241007-enlocale:en-usos:windows10-2004-x64system
  • submitted
    04/11/2024, 02:19

General

  • Target
    4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605.exe
  • Size 855KB
  • Sample241104-csbl6s1cmd
  • SHA256 4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Signatures

  • DcRat

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

  • Dcrat family
  • Modifies WinLogon for persistence 2 TTPs 6 IoCs
  • Process spawned unexpected child process 18 IoCs

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

  • DCRat payload 2 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

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

  • Executes dropped EXE 1 IoCs
  • Reads user/profile data of web browsers 3 TTPs

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

  • Adds Run key to start application 2 TTPs 12 IoCs
  • Looks up external IP address via web service 4 IoCs

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

  • Drops file in System32 directory 2 IoCs
  • Drops file in Program Files directory 6 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • System Network Configuration Discovery: Internet Connection Discovery 1 TTPs 1 IoCs

    Adversaries may check for Internet connectivity on compromised systems.

  • Modifies registry class 1 IoCs
  • Runs ping.exe 1 TTPs 1 IoCs
  • Scheduled Task/Job: Scheduled Task 1 TTPs 18 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 2 IoCs
  • Suspicious use of WriteProcessMemory 12 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\4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605.exe
    "C:\Users\Admin\AppData\Local\Temp\4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605.exe"
    1⤵
    • Modifies WinLogon for persistence
    • Checks computer location settings
    • Adds Run key to start application
    • Drops file in Program Files directory
    • Modifies registry class
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:5092
    • C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe
      "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe" /noconfig /fullpaths @"C:\Users\Admin\AppData\Local\Temp\14zuykxb\14zuykxb.cmdline"
      2⤵
      • Drops file in System32 directory
      • Suspicious use of WriteProcessMemory
      PID:3052
      • C:\Windows\Microsoft.NET\Framework64\v4.0.30319\cvtres.exe
        C:\Windows\Microsoft.NET\Framework64\v4.0.30319\cvtres.exe /NOLOGO /READONLY /MACHINE:IX86 "/OUT:C:\Users\Admin\AppData\Local\Temp\RESBC5B.tmp" "c:\Windows\System32\CSCB20E0BD88FBB48B3A841B3CEF85D3E5A.TMP"
        3⤵
          PID:1760
      • C:\Windows\System32\cmd.exe
        "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\GHW2TQxB8N.bat"
        2⤵
        • Suspicious use of WriteProcessMemory
        PID:3132
        • C:\Windows\system32\chcp.com
          chcp 65001
          3⤵
            PID:728
          • C:\Windows\system32\PING.EXE
            ping -n 10 localhost
            3⤵
            • System Network Configuration Discovery: Internet Connection Discovery
            • Runs ping.exe
            PID:2220
          • C:\Users\Admin\sihost.exe
            "C:\Users\Admin\sihost.exe"
            3⤵
            • Executes dropped EXE
            • Suspicious behavior: GetForegroundWindowSpam
            • Suspicious use of AdjustPrivilegeToken
            PID:4820
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "sppsvcs" /sc MINUTE /mo 8 /tr "'C:\Recovery\WindowsRE\sppsvc.exe'" /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:3940
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "sppsvc" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\sppsvc.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:2008
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "sppsvcs" /sc MINUTE /mo 13 /tr "'C:\Recovery\WindowsRE\sppsvc.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:2540
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 7 /tr "'C:\Recovery\WindowsRE\csrss.exe'" /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:3396
      • 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
        • Scheduled Task/Job: Scheduled Task
        PID:4208
      • 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
        • Scheduled Task/Job: Scheduled Task
        PID:2508
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "winlogonw" /sc MINUTE /mo 10 /tr "'C:\Program Files\Microsoft Office 15\winlogon.exe'" /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:2656
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "winlogon" /sc ONLOGON /tr "'C:\Program Files\Microsoft Office 15\winlogon.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:4004
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "winlogonw" /sc MINUTE /mo 6 /tr "'C:\Program Files\Microsoft Office 15\winlogon.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:808
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "sihosts" /sc MINUTE /mo 7 /tr "'C:\Users\Admin\sihost.exe'" /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:968
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "sihost" /sc ONLOGON /tr "'C:\Users\Admin\sihost.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:2804
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "sihosts" /sc MINUTE /mo 5 /tr "'C:\Users\Admin\sihost.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:1844
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "fontdrvhostf" /sc MINUTE /mo 13 /tr "'C:\Program Files\Windows Photo Viewer\uk-UA\fontdrvhost.exe'" /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:1920
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "fontdrvhost" /sc ONLOGON /tr "'C:\Program Files\Windows Photo Viewer\uk-UA\fontdrvhost.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:3028
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "fontdrvhostf" /sc MINUTE /mo 8 /tr "'C:\Program Files\Windows Photo Viewer\uk-UA\fontdrvhost.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:1064
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f825490796054" /sc MINUTE /mo 6 /tr "'C:\Users\Admin\AppData\Local\Temp\4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605.exe'" /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:1952
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605" /sc ONLOGON /tr "'C:\Users\Admin\AppData\Local\Temp\4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:2808
      • C:\Windows\system32\schtasks.exe
        schtasks.exe /create /tn "4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f825490796054" /sc MINUTE /mo 5 /tr "'C:\Users\Admin\AppData\Local\Temp\4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605.exe'" /rl HIGHEST /f
        1⤵
        • Process spawned unexpected child process
        • Scheduled Task/Job: Scheduled Task
        PID:3036

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

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            Downloads

            sppsvc.exe

            • Path C:\Recovery\WindowsRE\sppsvc.exe
            • Size 855KB
            • SHA256 4b1967b04039c9b7a23651043b38c895cca2eb560de30a960368f82549079605
            • MD5 SHA1 SHA512 SSDEEP

            GHW2TQxB8N.bat

            • Path C:\Users\Admin\AppData\Local\Temp\GHW2TQxB8N.bat
            • Size 153B
            • SHA256 b9009a17f930481062bfb9d6e7b94a4a2488863dbc0a76a34572fdf45da8693b
            • MD5 SHA1 SHA512

            RESBC5B.tmp

            • Path C:\Users\Admin\AppData\Local\Temp\RESBC5B.tmp
            • Size 1KB
            • SHA256 6da00b8254edbc43b444f62ba38ad4510fba7d7626154972e3cf4a7ba87e06bc
            • MD5 SHA1 SHA512

            14zuykxb.0.cs

            • Path \??\c:\Users\Admin\AppData\Local\Temp\14zuykxb\14zuykxb.0.cs
            • Size 364B
            • SHA256 4f1c47843600fc91f03179fa7947615a46881672dca6a648fc42cd044ccc368b
            • MD5 SHA1 SHA512

            14zuykxb.cmdline

            • Path \??\c:\Users\Admin\AppData\Local\Temp\14zuykxb\14zuykxb.cmdline
            • Size 235B
            • SHA256 1bec1c0ab9d7e4ea78885b6bb3ae5d85d2d54169f9451e05e948dfba23506d43
            • MD5 SHA1 SHA512

            CSCB20E0BD88FBB48B3A841B3CEF85D3E5A.TMP

            • Path \??\c:\Windows\System32\CSCB20E0BD88FBB48B3A841B3CEF85D3E5A.TMP
            • Size 1KB
            • SHA256 97ee1cac3965d9cc55a60f20206f384719431f19ac96bdc52b93a98de51a639b
            • MD5 SHA1 SHA512

            memory/5092-8-0x000000001BAF0000-0x000000001BB40000-memory.dmp

            memory/5092-32-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-12-0x0000000002F40000-0x0000000002F4C000-memory.dmp

            memory/5092-14-0x0000000002F50000-0x0000000002F5E000-memory.dmp

            memory/5092-16-0x0000000002F60000-0x0000000002F68000-memory.dmp

            memory/5092-17-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-19-0x0000000003100000-0x000000000310C000-memory.dmp

            memory/5092-27-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-0-0x00007FFBFD203000-0x00007FFBFD205000-memory.dmp

            memory/5092-10-0x00000000030A0000-0x00000000030B8000-memory.dmp

            memory/5092-33-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-34-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-7-0x0000000003080000-0x000000000309C000-memory.dmp

            memory/5092-5-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-4-0x0000000002F30000-0x0000000002F3E000-memory.dmp

            memory/5092-2-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-47-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-53-0x00007FFBFD200000-0x00007FFBFDCC1000-memory.dmp

            memory/5092-1-0x0000000000E00000-0x0000000000EDC000-memory.dmp