Analysis

  • max time kernel
    138s
  • max time network
    155s
  • platform
    windows10_x64
  • resource
    win10-en
  • submitted
    09/09/2021, 11:58

General

  • Target
    c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe
  • Size 792KB
  • Sample210909-n471asbcel
  • SHA256 c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f
  • MD5 SHA1 SHA512

Malware Config

Extracted

Family
  • vidar

Version
  • 40.5

Botnet
  • 517

C2
  • https://gheorghip.tumblr.com/

Attributes
  • profile_id

    517

Signatures

  • Detected Djvu ransomeware 8 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 4 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 4 IoCs

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

  • Suspicious use of SetThreadContext 4 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 14 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 56 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe
    "C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:3668
    • C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe
      "C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe"
      2⤵
      • Adds Run key to start application
      • Modifies system certificate store
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:2824
      • C:\Windows\SysWOW64\icacls.exe
        icacls "C:\Users\Admin\AppData\Local\d7e8a533-1b9a-457b-8948-0f22361380b9" /deny *S-1-1-0:(OI)(CI)(DE,DC)
        3⤵
        • Modifies file permissions
        PID:1020
      • C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe
        "C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe" --Admin IsNotAutoStart IsNotTask
        3⤵
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:3184
        • C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe
          "C:\Users\Admin\AppData\Local\Temp\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe" --Admin IsNotAutoStart IsNotTask
          4⤵
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of WriteProcessMemory
          PID:1452
          • C:\Users\Admin\AppData\Local\14415a33-7dd2-4be7-9748-3f972992342e\build2.exe
            "C:\Users\Admin\AppData\Local\14415a33-7dd2-4be7-9748-3f972992342e\build2.exe"
            5⤵
            • Executes dropped EXE
            • Suspicious use of SetThreadContext
            • Suspicious use of WriteProcessMemory
            PID:3604
            • C:\Users\Admin\AppData\Local\14415a33-7dd2-4be7-9748-3f972992342e\build2.exe
              "C:\Users\Admin\AppData\Local\14415a33-7dd2-4be7-9748-3f972992342e\build2.exe"
              6⤵
              • Executes dropped EXE
              • Loads dropped DLL
              • Checks processor information in registry
              • Suspicious behavior: EnumeratesProcesses
              • Suspicious use of WriteProcessMemory
              PID:1876
              • 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\14415a33-7dd2-4be7-9748-3f972992342e\build2.exe" & del C:\ProgramData\*.dll & exit
                7⤵
                • Suspicious use of WriteProcessMemory
                PID:2288
                • C:\Windows\SysWOW64\taskkill.exe
                  taskkill /im build2.exe /f
                  8⤵
                  • Kills process with taskkill
                  • Suspicious use of AdjustPrivilegeToken
                  PID:2236
                • C:\Windows\SysWOW64\timeout.exe
                  timeout /t 6
                  8⤵
                  • Delays execution with timeout.exe
                  PID:3856
  • C:\Users\Admin\AppData\Local\d7e8a533-1b9a-457b-8948-0f22361380b9\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe
    C:\Users\Admin\AppData\Local\d7e8a533-1b9a-457b-8948-0f22361380b9\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe --Task
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:2392
    • C:\Users\Admin\AppData\Local\d7e8a533-1b9a-457b-8948-0f22361380b9\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe
      C:\Users\Admin\AppData\Local\d7e8a533-1b9a-457b-8948-0f22361380b9\c90d3fe9641d27a59510e20001bc315dc1b76972f03e910e2d71bd6cde0e983f.exe --Task
      2⤵
      • Executes dropped EXE
      • Suspicious behavior: EnumeratesProcesses
      PID:1568

Network

        MITRE ATT&CK Enterprise v6

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        Downloads

        memory/1452-124-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/1568-152-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/1876-136-0x0000000000400000-0x00000000004D5000-memory.dmp

        memory/1876-132-0x0000000000400000-0x00000000004D5000-memory.dmp

        memory/2824-118-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/2824-115-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/3604-135-0x0000000002550000-0x0000000002622000-memory.dmp

        memory/3668-117-0x0000000004140000-0x000000000425B000-memory.dmp