Analysis

  • max time kernel
    138s
  • max time network
    133s
  • platform
    windows10_x64
  • resource
    win10v20210408
  • submitted
    04/09/2021, 06:17

General

  • Target
    0fbd60e2b0253dddc32ef110d0cd71d4.exe
  • Size 838KB
  • Sample210904-g12wjsdhf4
  • SHA256 9a9f3b0dbf3655264bdabd0e02127d74b341522c669d3eb11b22b2e2da97867f
  • 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.

  • Vidar Stealer 7 IoCs
  • Downloads MZ/PE file
  • Executes dropped EXE 8 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 6 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.

  • Creates scheduled task(s) 1 TTPs 2 IoCs

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

  • 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 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe
    "C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:528
    • C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe
      "C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe"
      2⤵
      • Adds Run key to start application
      • Modifies system certificate store
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:3372
      • C:\Windows\SysWOW64\icacls.exe
        icacls "C:\Users\Admin\AppData\Local\9801a31c-a1b2-4ce4-b20a-920a01d5826f" /deny *S-1-1-0:(OI)(CI)(DE,DC)
        3⤵
        • Modifies file permissions
        PID:2060
      • C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe
        "C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe" --Admin IsNotAutoStart IsNotTask
        3⤵
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:1340
        • C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe
          "C:\Users\Admin\AppData\Local\Temp\0fbd60e2b0253dddc32ef110d0cd71d4.exe" --Admin IsNotAutoStart IsNotTask
          4⤵
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of WriteProcessMemory
          PID:3460
          • C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build2.exe
            "C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build2.exe"
            5⤵
            • Executes dropped EXE
            • Suspicious use of SetThreadContext
            • Suspicious use of WriteProcessMemory
            PID:3096
            • C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build2.exe
              "C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build2.exe"
              6⤵
              • Executes dropped EXE
              • Loads dropped DLL
              • Checks processor information in registry
              • Suspicious behavior: EnumeratesProcesses
              • Suspicious use of WriteProcessMemory
              PID:3260
              • 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\c105b0c6-89d6-41ae-a250-7d735baf7970\build2.exe" & del C:\ProgramData\*.dll & exit
                7⤵
                • Suspicious use of WriteProcessMemory
                PID:184
                • C:\Windows\SysWOW64\taskkill.exe
                  taskkill /im build2.exe /f
                  8⤵
                  • Kills process with taskkill
                  • Suspicious use of AdjustPrivilegeToken
                  PID:188
                • C:\Windows\SysWOW64\timeout.exe
                  timeout /t 6
                  8⤵
                  • Delays execution with timeout.exe
                  PID:508
          • C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build3.exe
            "C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build3.exe"
            5⤵
            • Executes dropped EXE
            • Suspicious use of SetThreadContext
            • Suspicious use of WriteProcessMemory
            PID:2740
            • C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build3.exe
              "C:\Users\Admin\AppData\Local\c105b0c6-89d6-41ae-a250-7d735baf7970\build3.exe"
              6⤵
              • Executes dropped EXE
              • Suspicious use of WriteProcessMemory
              PID:3208
              • C:\Windows\SysWOW64\schtasks.exe
                /C /create /F /sc minute /mo 1 /tn "Azure-Update-Task" /tr "C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe"
                7⤵
                • Creates scheduled task(s)
                PID:2220
  • C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
    C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:1188
    • C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
      C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
      2⤵
      • Executes dropped EXE
      PID:4092
      • C:\Windows\SysWOW64\schtasks.exe
        /C /create /F /sc minute /mo 1 /tn "Azure-Update-Task" /tr "C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe"
        3⤵
        • Creates scheduled task(s)
        PID:704
  • C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
    C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    PID:2908
    • C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
      C:\Users\Admin\AppData\Roaming\Microsoft\Network\mstsca.exe
      2⤵
      • Executes dropped EXE
      PID:820

Network

        MITRE ATT&CK Enterprise v6

        Replay Monitor

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        Downloads

        memory/528-116-0x0000000004140000-0x000000000425B000-memory.dmp

        memory/1188-162-0x0000000003250000-0x00000000032FE000-memory.dmp

        memory/2740-145-0x00000000032A0000-0x00000000033EA000-memory.dmp

        memory/2908-167-0x0000000003250000-0x000000000339A000-memory.dmp

        memory/3096-134-0x00000000047B0000-0x0000000004883000-memory.dmp

        memory/3208-146-0x0000000000400000-0x0000000000406000-memory.dmp

        memory/3208-141-0x0000000000400000-0x0000000000406000-memory.dmp

        memory/3260-131-0x0000000000400000-0x00000000004D7000-memory.dmp

        memory/3260-135-0x0000000000400000-0x00000000004D7000-memory.dmp

        memory/3372-117-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/3372-114-0x0000000000400000-0x0000000000537000-memory.dmp

        memory/3460-127-0x0000000000400000-0x0000000000537000-memory.dmp