Analysis

  • max time kernel
    101s
  • max time network
    105s
  • platform
    windows7_x64
  • resource
    win7v20210408
  • submitted
    05/05/2021, 13:54

General

  • Target
    build.exe
  • Size 831KB
  • Sample210505-vce8dr9192
  • SHA256 3763170476b8a4c3cb592cbea6c4471ba2ea2463db9f7839fda502ef0a06b092
  • MD5 SHA1 SHA512

Malware Config

Signatures

  • Deletes Windows Defender Definitions 2 TTPs 1 IoCs

    Uses mpcmdrun utility to delete all AV definitions.

  • Disables Task Manager via registry modification
  • Downloads MZ/PE file
  • Drops file in Drivers directory 1 IoCs
  • Executes dropped EXE 4 IoCs
  • Loads dropped DLL 12 IoCs
  • Modifies file permissions 1 TTPs 1 IoCs
  • Adds Run key to start application 2 TTPs 1 IoCs
  • Looks up external IP address via web service 3 IoCs

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

  • Enumerates physical storage devices 1 TTPs

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

  • Modifies system certificate store 2 TTPs 7 IoCs
  • Suspicious behavior: EnumeratesProcesses 10 IoCs
  • Suspicious use of AdjustPrivilegeToken 3 IoCs
  • Suspicious use of WriteProcessMemory 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\build.exe
    "C:\Users\Admin\AppData\Local\Temp\build.exe"
    1⤵
    • Adds Run key to start application
    • Modifies system certificate store
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    PID:1820
    • C:\Windows\SysWOW64\icacls.exe
      icacls "C:\Users\Admin\AppData\Local\fbc87291-59a8-4fcd-8bc8-4722b9535fda" /deny *S-1-1-0:(OI)(CI)(DE,DC)
      2⤵
      • Modifies file permissions
      PID:1476
    • C:\Users\Admin\AppData\Local\Temp\build.exe
      "C:\Users\Admin\AppData\Local\Temp\build.exe" --Admin IsNotAutoStart IsNotTask
      2⤵
      • Loads dropped DLL
      • Modifies system certificate store
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:1872
      • C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\updatewin1.exe
        "C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\updatewin1.exe"
        3⤵
        • Executes dropped EXE
        • Loads dropped DLL
        • Suspicious use of WriteProcessMemory
        PID:1744
        • C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\updatewin1.exe
          "C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\updatewin1.exe" --Admin
          4⤵
          • Executes dropped EXE
          • Loads dropped DLL
          • Suspicious use of WriteProcessMemory
          PID:240
          • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
            powershell -Command Set-ExecutionPolicy -Scope CurrentUser RemoteSigned
            5⤵
            • Suspicious behavior: EnumeratesProcesses
            • Suspicious use of AdjustPrivilegeToken
            PID:1700
          • 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}"
            5⤵
            • Suspicious behavior: EnumeratesProcesses
            • Suspicious use of AdjustPrivilegeToken
            • Suspicious use of WriteProcessMemory
            PID:1736
            • 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
              6⤵
              • Suspicious behavior: EnumeratesProcesses
              • Suspicious use of AdjustPrivilegeToken
              PID:1616
          • C:\Program Files\Windows Defender\mpcmdrun.exe
            "C:\Program Files\Windows Defender\mpcmdrun.exe" -removedefinitions -all
            5⤵
            • Deletes Windows Defender Definitions
            PID:1256
          • C:\Windows\SysWOW64\cmd.exe
            cmd /c ""C:\Users\Admin\AppData\Local\Temp\delself.bat""
            5⤵
              PID:900
        • C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\updatewin2.exe
          "C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\updatewin2.exe"
          3⤵
          • Drops file in Drivers directory
          • Executes dropped EXE
          PID:1436
        • C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\5.exe
          "C:\Users\Admin\AppData\Local\dd20675e-9012-4851-86d8-fb7eb1882036\5.exe"
          3⤵
          • Executes dropped EXE
          • Modifies system certificate store
          PID:1588

    Network

          MITRE ATT&CK Enterprise v6

          Replay Monitor

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          Downloads

          memory/240-94-0x0000000000400000-0x000000000044D000-memory.dmp

          memory/1436-100-0x0000000000400000-0x000000000044D000-memory.dmp

          memory/1588-110-0x00000000002B0000-0x0000000000347000-memory.dmp

          memory/1588-111-0x0000000000400000-0x00000000004B4000-memory.dmp

          memory/1616-151-0x00000000025E0000-0x00000000025E1000-memory.dmp

          memory/1616-162-0x0000000005820000-0x0000000005821000-memory.dmp

          memory/1616-154-0x0000000002770000-0x0000000002771000-memory.dmp

          memory/1616-179-0x0000000006470000-0x0000000006471000-memory.dmp

          memory/1616-157-0x0000000005420000-0x0000000005421000-memory.dmp

          memory/1616-158-0x0000000004AB0000-0x0000000004AB1000-memory.dmp

          memory/1616-178-0x0000000006460000-0x0000000006461000-memory.dmp

          memory/1616-165-0x0000000006320000-0x0000000006321000-memory.dmp

          memory/1616-159-0x0000000004AB2000-0x0000000004AB3000-memory.dmp

          memory/1700-112-0x0000000005360000-0x0000000005361000-memory.dmp

          memory/1700-99-0x0000000001F70000-0x0000000001F71000-memory.dmp

          memory/1700-108-0x0000000002630000-0x0000000002631000-memory.dmp

          memory/1700-120-0x00000000057D0000-0x00000000057D1000-memory.dmp

          memory/1700-103-0x0000000002000000-0x0000000002C4A000-memory.dmp

          memory/1700-115-0x0000000005730000-0x0000000005731000-memory.dmp

          memory/1700-102-0x0000000004830000-0x0000000004831000-memory.dmp

          memory/1700-131-0x000000007EF30000-0x000000007EF31000-memory.dmp

          memory/1700-128-0x0000000006370000-0x0000000006371000-memory.dmp

          memory/1700-101-0x0000000002000000-0x0000000002C4A000-memory.dmp

          memory/1700-121-0x0000000005830000-0x0000000005831000-memory.dmp

          memory/1736-135-0x0000000005320000-0x0000000005321000-memory.dmp

          memory/1736-146-0x00000000061E0000-0x00000000061E1000-memory.dmp

          memory/1736-136-0x0000000005420000-0x0000000005421000-memory.dmp

          memory/1736-134-0x0000000004A60000-0x0000000004A61000-memory.dmp

          memory/1736-133-0x0000000002400000-0x0000000002401000-memory.dmp

          memory/1744-93-0x0000000000400000-0x000000000044D000-memory.dmp

          memory/1820-60-0x0000000076641000-0x0000000076643000-memory.dmp

          memory/1820-62-0x0000000000400000-0x00000000008C8000-memory.dmp

          memory/1820-61-0x00000000008D0000-0x00000000009EA000-memory.dmp

          memory/1872-72-0x0000000000400000-0x00000000008C8000-memory.dmp