Analysis

  • max time kernel
    150s
  • max time network
    153s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20260513-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20260513-enlocale:en-usos:windows10-2004-x64systemwindows
  • submitted
    22/05/2026, 15:38

General

  • Target
    tmpucz_f67f.exe
  • Size 708KB
  • Sample260522-s26rnsav2s
  • SHA256 9d869ef931d27ef1137692fce35bea54fa53df4969cd1d9929cb94d7ab2a7181
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Signatures

  • Modifies WinLogon for persistence 2 TTPs 3 IoCs
  • UAC bypass 3 TTPs 12 IoCs
  • Adds policy Run key to start application 2 TTPs 29 IoCs
  • Disables RegEdit via registry modification 6 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Executes dropped EXE 2 IoCs
  • Impair Defenses: Safe Mode Boot 1 TTPs 6 IoCs
  • Adds Run key to start application 2 TTPs 64 IoCs
  • Checks whether UAC is enabled 1 TTPs 6 IoCs
  • Hijack Execution Flow: Executable Installer File Permissions Weakness 1 TTPs 3 IoCs

    Possible Turn off User Account Control's privilege elevation for standard users.

  • Looks up external IP address via web service 9 IoCs

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

  • Drops file in System32 directory 4 IoCs
  • Drops file in Program Files directory 4 IoCs
  • Drops file in Windows directory 4 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • System Location Discovery: System Language Discovery 1 TTPs 3 IoCs

    Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

  • Modifies registry class 3 IoCs
  • Suspicious behavior: EnumeratesProcesses 20 IoCs
  • Suspicious behavior: GetForegroundWindowSpam 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 2 IoCs
  • System policy modification 1 TTPs 36 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\tmpucz_f67f.exe
    "C:\Users\Admin\AppData\Local\Temp\tmpucz_f67f.exe"
    1⤵
    • Modifies WinLogon for persistence
    • UAC bypass
    • Adds policy Run key to start application
    • Disables RegEdit via registry modification
    • Checks computer location settings
    • Adds Run key to start application
    • Checks whether UAC is enabled
    • Hijack Execution Flow: Executable Installer File Permissions Weakness
    • System Location Discovery: System Language Discovery
    • Modifies registry class
    • Suspicious use of WriteProcessMemory
    • System policy modification
    PID:4652
    • C:\Users\Admin\AppData\Local\Temp\ycflx.exe
      "C:\Users\Admin\AppData\Local\Temp\ycflx.exe" "-"
      2⤵
      • Modifies WinLogon for persistence
      • UAC bypass
      • Adds policy Run key to start application
      • Disables RegEdit via registry modification
      • Executes dropped EXE
      • Impair Defenses: Safe Mode Boot
      • Adds Run key to start application
      • Checks whether UAC is enabled
      • Hijack Execution Flow: Executable Installer File Permissions Weakness
      • Drops file in System32 directory
      • Drops file in Program Files directory
      • Drops file in Windows directory
      • System Location Discovery: System Language Discovery
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of AdjustPrivilegeToken
      • System policy modification
      PID:5116
    • C:\Users\Admin\AppData\Local\Temp\ycflx.exe
      "C:\Users\Admin\AppData\Local\Temp\ycflx.exe" "-"
      2⤵
      • Modifies WinLogon for persistence
      • UAC bypass
      • Adds policy Run key to start application
      • Disables RegEdit via registry modification
      • Executes dropped EXE
      • Adds Run key to start application
      • Checks whether UAC is enabled
      • Hijack Execution Flow: Executable Installer File Permissions Weakness
      • System Location Discovery: System Language Discovery
      • Modifies registry class
      • Suspicious behavior: GetForegroundWindowSpam
      • System policy modification
      PID:2248
  • C:\Windows\explorer.exe
    Explorer.exe
    1⤵
    • Modifies registry class
    PID:5032
  • C:\Windows\System32\rundll32.exe
    C:\Windows\System32\rundll32.exe C:\Windows\System32\shell32.dll,SHCreateLocalServerRunDll {9aa46009-3ce0-458a-a354-715610a075e6} -Embedding
    1⤵
      PID:364

    Network

          MITRE ATT&CK Enterprise v16

          Replay Monitor

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          Downloads

          ycflx.exe

          • Path C:\Users\Admin\AppData\Local\Temp\ycflx.exe
          • Size 1.3MB
          • SHA256 63cbdbcaf87b4164d6cede7b7b71768b1da2e2a2d6457468082f95c3c5ef5c98
          • MD5 SHA1 SHA512 SSDEEP TLSH

          vkypmdmfzjjuyboubsxmarofohbllwadqwduzo.tqh

          • Path C:\Users\Admin\AppData\Local\vkypmdmfzjjuyboubsxmarofohbllwadqwduzo.tqh
          • Size 3KB
          • SHA256 0974befcdc85dd851db9f88c0f201f5d13e91a8d1da5cd36f0332682a3b38e9e
          • MD5 SHA1 SHA512 TLSH

          ycflxdbjsrggzrtokqkorxjpnve.ssl

          • Path C:\Users\Admin\AppData\Local\ycflxdbjsrggzrtokqkorxjpnve.ssl
          • Size 272B
          • SHA256 3950a01703d3620d8468c110363b621236e99e0a815577df535192d97dfe5cee
          • MD5 SHA1 SHA512 TLSH