Analysis

  • max time kernel
    76s
  • max time network
    141s
  • platform
    windows10_x64
  • resource
    win10v20210408
  • submitted
    03/09/2021, 09:06

General

  • Target
    240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe
  • Size 788KB
  • Sample210903-k2rnragacn
  • SHA256 240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd
  • MD5 SHA1 SHA512

Malware Config

Extracted

Family
  • vidar

Version
  • 40.4

Botnet
  • 517

C2
  • https://romkaxarit.tumblr.com/

Attributes
  • profile_id

    517

Signatures

  • Detected Djvu ransomeware 6 IoCs
  • Djvu Ransomware

    Ransomware which is a variant of the STOP family.

  • Vidar

    Vidar is an infostealer based on Arkei stealer.

  • suricata: ET MALWARE Potential Dridex.Maldoc Minimal Executable Request

    suricata: ET MALWARE Potential Dridex.Maldoc Minimal Executable Request

  • suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt)

    suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt)

  • suricata: ET MALWARE Vidar/Arkei Stealer Client Data Upload

    suricata: ET MALWARE Vidar/Arkei Stealer Client Data Upload

  • suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer Data Exfil

    suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer Data Exfil

  • Vidar Stealer 4 IoCs
  • Downloads MZ/PE file
  • Executes dropped EXE 2 IoCs
  • Loads dropped DLL 2 IoCs
  • Modifies file permissions 1 TTPs 1 IoCs
  • Reads user/profile data of web browsers 2 TTPs

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

  • Accesses 2FA software files, possible credential harvesting 2 TTPs
  • Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
  • Adds Run key to start application 2 TTPs 1 IoCs
  • Checks installed software on the system 1 TTPs

    Looks up Uninstall key entries in the registry to enumerate software on the system.

  • Looks up external IP address via web service 3 IoCs

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

  • Suspicious use of SetThreadContext 3 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Checks processor information in registry 2 TTPs 2 IoCs

    Processor information is often read in order to detect sandboxing environments.

  • Delays execution with timeout.exe 1 IoCs
  • Kills process with taskkill 1 IoCs
  • Modifies system certificate store 2 TTPs 2 IoCs
  • Suspicious behavior: EnumeratesProcesses 12 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 46 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe
    "C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:656
    • C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe
      "C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe"
      2⤵
      • Adds Run key to start application
      • Modifies system certificate store
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:3856
      • C:\Windows\SysWOW64\icacls.exe
        icacls "C:\Users\Admin\AppData\Local\fef7c4ae-4245-4d95-827e-64116561d4d1" /deny *S-1-1-0:(OI)(CI)(DE,DC)
        3⤵
        • Modifies file permissions
        PID:1148
      • C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe
        "C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe" --Admin IsNotAutoStart IsNotTask
        3⤵
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:3104
        • C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe
          "C:\Users\Admin\AppData\Local\Temp\240da2ce69194d4816e25503e3c096a05725cf2bfc79a7a4d565c46d07589ebd.exe" --Admin IsNotAutoStart IsNotTask
          4⤵
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of WriteProcessMemory
          PID:3344
          • C:\Users\Admin\AppData\Local\38530850-b233-4d4c-a768-ba4f17b83808\build2.exe
            "C:\Users\Admin\AppData\Local\38530850-b233-4d4c-a768-ba4f17b83808\build2.exe"
            5⤵
            • Executes dropped EXE
            • Suspicious use of SetThreadContext
            • Suspicious use of WriteProcessMemory
            PID:808
            • C:\Users\Admin\AppData\Local\38530850-b233-4d4c-a768-ba4f17b83808\build2.exe
              "C:\Users\Admin\AppData\Local\38530850-b233-4d4c-a768-ba4f17b83808\build2.exe"
              6⤵
              • Executes dropped EXE
              • Loads dropped DLL
              • Checks processor information in registry
              • Suspicious behavior: EnumeratesProcesses
              • Suspicious use of WriteProcessMemory
              PID:3868
              • C:\Windows\SysWOW64\cmd.exe
                "C:\Windows\System32\cmd.exe" /c taskkill /im build2.exe /f & timeout /t 6 & del /f /q "C:\Users\Admin\AppData\Local\38530850-b233-4d4c-a768-ba4f17b83808\build2.exe" & del C:\ProgramData\*.dll & exit
                7⤵
                • Suspicious use of WriteProcessMemory
                PID:3200
                • C:\Windows\SysWOW64\taskkill.exe
                  taskkill /im build2.exe /f
                  8⤵
                  • Kills process with taskkill
                  • Suspicious use of AdjustPrivilegeToken
                  PID:512
                • C:\Windows\SysWOW64\timeout.exe
                  timeout /t 6
                  8⤵
                  • Delays execution with timeout.exe
                  PID:3616

Network

        MITRE ATT&CK Enterprise v6

        Replay Monitor

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        Downloads

        memory/656-116-0x0000000004350000-0x000000000446B000-memory.dmp

        memory/808-134-0x00000000048B0000-0x0000000004983000-memory.dmp

        memory/3344-127-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/3856-117-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/3856-114-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/3868-135-0x0000000000400000-0x00000000004D7000-memory.dmp

        memory/3868-131-0x0000000000400000-0x00000000004D7000-memory.dmp