Analysis

  • max time kernel
    67s
  • max time network
    141s
  • platform
    windows10_x64
  • resource
    win10v20210410
  • submitted
    08/06/2021, 19:29

General

  • Target
    bf45aaa2a719be3100e203b65989f15f.exe
  • Size 800KB
  • Sample210608-2x629ge296
  • SHA256 cf0a70e19ceb453b5cc477ec510e6fbd8639ee114d4f182a79e150b23dcd09c2
  • MD5 SHA1 SHA512

Malware Config

Extracted

Family
  • vidar

Version
  • 39.3

Botnet
  • 517

C2
  • https://bandakere.tumblr.com

Attributes
  • profile_id

    517

Signatures

  • Deletes Windows Defender Definitions 2 TTPs 1 IoCs

    Uses mpcmdrun utility to delete all AV definitions.

  • Djvu Ransomware

    Ransomware which is a variant of the STOP family.

  • Vidar

    Vidar is an infostealer based on Arkei stealer.

  • Vidar Stealer 4 IoCs
  • Disables Task Manager via registry modification
  • Downloads MZ/PE file
  • Drops file in Drivers directory 1 IoCs
  • Executes dropped EXE 5 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 22 IoCs
  • Suspicious use of AdjustPrivilegeToken 4 IoCs
  • Suspicious use of WriteProcessMemory 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe
    "C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:3892
    • C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe
      "C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe"
      2⤵
      • Adds Run key to start application
      • Modifies system certificate store
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:2900
      • C:\Windows\SysWOW64\icacls.exe
        icacls "C:\Users\Admin\AppData\Local\d27d547b-466c-49bc-a94f-04f72e1150d9" /deny *S-1-1-0:(OI)(CI)(DE,DC)
        3⤵
        • Modifies file permissions
        PID:3004
      • C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe
        "C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe" --Admin IsNotAutoStart IsNotTask
        3⤵
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:1056
        • C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe
          "C:\Users\Admin\AppData\Local\Temp\bf45aaa2a719be3100e203b65989f15f.exe" --Admin IsNotAutoStart IsNotTask
          4⤵
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of WriteProcessMemory
          PID:1852
          • C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\updatewin1.exe
            "C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\updatewin1.exe"
            5⤵
            • Executes dropped EXE
            • Suspicious use of WriteProcessMemory
            PID:900
            • C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\updatewin1.exe
              "C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\updatewin1.exe" --Admin
              6⤵
              • Executes dropped EXE
              • Suspicious use of WriteProcessMemory
              PID:2348
              • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
                powershell -Command Set-ExecutionPolicy -Scope CurrentUser RemoteSigned
                7⤵
                • Suspicious behavior: EnumeratesProcesses
                • Suspicious use of AdjustPrivilegeToken
                PID:3892
              • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
                powershell -NoProfile -ExecutionPolicy Bypass -Command "& {Start-Process PowerShell -ArgumentList '-NoProfile -ExecutionPolicy Bypass -File ""C:\Users\Admin\AppData\Local\script.ps1""' -Verb RunAs}"
                7⤵
                • Suspicious behavior: EnumeratesProcesses
                • Suspicious use of AdjustPrivilegeToken
                • Suspicious use of WriteProcessMemory
                PID:1952
                • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
                  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -ExecutionPolicy Bypass -File "C:\Users\Admin\AppData\Local\script.ps1
                  8⤵
                  • Suspicious behavior: EnumeratesProcesses
                  • Suspicious use of AdjustPrivilegeToken
                  PID:1656
              • C:\Program Files\Windows Defender\mpcmdrun.exe
                "C:\Program Files\Windows Defender\mpcmdrun.exe" -removedefinitions -all
                7⤵
                • Deletes Windows Defender Definitions
                PID:3740
              • C:\Windows\SysWOW64\cmd.exe
                C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\delself.bat""
                7⤵
                  PID:2056
            • C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\updatewin2.exe
              "C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\updatewin2.exe"
              5⤵
              • Drops file in Drivers directory
              • Executes dropped EXE
              PID:3844
            • C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\5.exe
              "C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\5.exe"
              5⤵
              • Executes dropped EXE
              • Suspicious use of SetThreadContext
              • Suspicious use of WriteProcessMemory
              PID:2588
              • C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\5.exe
                "C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\5.exe"
                6⤵
                • Executes dropped EXE
                • Loads dropped DLL
                • Checks processor information in registry
                • Suspicious behavior: EnumeratesProcesses
                • Suspicious use of WriteProcessMemory
                PID:3884
                • C:\Windows\SysWOW64\cmd.exe
                  "C:\Windows\System32\cmd.exe" /c taskkill /im 5.exe /f & timeout /t 6 & del /f /q "C:\Users\Admin\AppData\Local\3af4a79c-9f54-45b6-98a1-cbeec266b8e9\5.exe" & del C:\ProgramData\*.dll & exit
                  7⤵
                  • Suspicious use of WriteProcessMemory
                  PID:2684
                  • C:\Windows\SysWOW64\taskkill.exe
                    taskkill /im 5.exe /f
                    8⤵
                    • Kills process with taskkill
                    • Suspicious use of AdjustPrivilegeToken
                    PID:3128
                  • C:\Windows\SysWOW64\timeout.exe
                    timeout /t 6
                    8⤵
                    • Delays execution with timeout.exe
                    PID:748

    Network

          MITRE ATT&CK Enterprise v6

          Replay Monitor

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          Downloads

          memory/900-137-0x0000000000400000-0x000000000044D000-memory.dmp

          memory/1656-233-0x000000007EA10000-0x000000007EA11000-memory.dmp

          memory/1656-228-0x00000000049E2000-0x00000000049E3000-memory.dmp

          memory/1656-227-0x00000000049E0000-0x00000000049E1000-memory.dmp

          memory/1656-234-0x00000000049E3000-0x00000000049E4000-memory.dmp

          memory/1852-124-0x0000000000400000-0x0000000000537000-memory.dmp

          memory/1952-220-0x0000000006750000-0x0000000006751000-memory.dmp

          memory/1952-226-0x0000000006753000-0x0000000006754000-memory.dmp

          memory/1952-221-0x0000000006752000-0x0000000006753000-memory.dmp

          memory/2348-153-0x0000000000400000-0x000000000044D000-memory.dmp

          memory/2588-157-0x00000000021B0000-0x0000000002248000-memory.dmp

          memory/2900-117-0x0000000000400000-0x0000000000537000-memory.dmp

          memory/2900-114-0x0000000000400000-0x0000000000537000-memory.dmp

          memory/3844-141-0x0000000000400000-0x000000000044D000-memory.dmp

          memory/3884-147-0x0000000000400000-0x000000000049B000-memory.dmp

          memory/3884-158-0x0000000000400000-0x000000000049B000-memory.dmp

          memory/3892-183-0x0000000009AB0000-0x0000000009AB1000-memory.dmp

          memory/3892-151-0x00000000081B0000-0x00000000081B1000-memory.dmp

          memory/3892-152-0x0000000007FD0000-0x0000000007FD1000-memory.dmp

          memory/3892-150-0x00000000078F0000-0x00000000078F1000-memory.dmp

          memory/3892-216-0x0000000007363000-0x0000000007364000-memory.dmp

          memory/3892-215-0x0000000007366000-0x0000000007368000-memory.dmp

          memory/3892-214-0x000000007EC10000-0x000000007EC11000-memory.dmp

          memory/3892-146-0x00000000079A0000-0x00000000079A1000-memory.dmp

          memory/3892-145-0x0000000007210000-0x0000000007211000-memory.dmp

          memory/3892-184-0x0000000009C60000-0x0000000009C61000-memory.dmp

          memory/3892-154-0x0000000007360000-0x0000000007361000-memory.dmp

          memory/3892-178-0x0000000009940000-0x0000000009941000-memory.dmp

          memory/3892-171-0x0000000009980000-0x00000000099B3000-memory.dmp

          memory/3892-155-0x0000000008220000-0x0000000008221000-memory.dmp

          memory/3892-156-0x0000000007362000-0x0000000007363000-memory.dmp

          memory/3892-161-0x0000000008A40000-0x0000000008A41000-memory.dmp

          memory/3892-160-0x00000000086F0000-0x00000000086F1000-memory.dmp

          memory/3892-116-0x00000000022D0000-0x00000000023EB000-memory.dmp

          memory/3892-159-0x0000000008590000-0x0000000008591000-memory.dmp