Analysis

  • max time kernel
    7s
  • max time network
    41s
  • platform
    windows11-ltsc_2024_x64
  • resource
    win11ltsc2024-20260911-en
  • resource tags

    arch:x64arch:x86image:win11ltsc2024-20260911-enlocale:en-usos:windows11-ltsc_2024-x64systemwindows
  • submitted
    28/09/2026, 12:45

Errors

Reason
Machine shutdown

General

  • Target
    chernobyl mbr .exe
  • Size 3.2MB
  • Sample260928-py4alathmf
  • SHA256 79b15418ed5af280f8563206b5d449bb67b83f85420fa06912783b1cdde06576
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Signatures

  • Event Triggered Execution: Component Object Model Hijacking 1 TTPs

    Adversaries may establish persistence by executing malicious content triggered by hijacked references to Component Object Model (COM) objects.

  • Executes dropped EXE 1 IoCs
  • Modifies system executable filetype association 2 TTPs 16 IoCs
  • Writes to the Master Boot Record (MBR) 1 TTPs 1 IoCs

    Bootkits write to the MBR to gain persistence at a level below the operating system.

  • Enumerates physical storage devices 1 TTPs

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

  • Executes a command shell one-liner 1 TTPs 1 IoCs

    Execution of a cmd.exe one-liner (/c "close" or /k "keep") is a common script/loader stage.

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

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

  • Modifies registry class 64 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 3 IoCs
  • Uses Task Scheduler COM API 1 TTPs

    The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.

  • Uses Volume Shadow Copy WMI provider

    The Volume Shadow Copy service is used to manage backups/snapshots.

Processes

  • C:\Users\Admin\AppData\Local\Temp\chernobyl mbr .exe
    "C:\Users\Admin\AppData\Local\Temp\chernobyl mbr .exe"
    1⤵
    • Writes to the Master Boot Record (MBR)
    • Suspicious use of WriteProcessMemory
    PID:5288
    • C:\Windows\System32\cmd.exe
      "C:\Windows\System32\cmd.exe" /k reg delete HKCR /f
      2⤵
      • Executes a command shell one-liner
      • Suspicious use of WriteProcessMemory
      PID:5012
      • C:\Windows\system32\reg.exe
        reg delete HKCR /f
        3⤵
        • Modifies system executable filetype association
        • Modifies registry class
        PID:1068
    • C:\Users\Admin\AppData\Local\Temp\nasm.exe
      "nasm.exe" -f bin mbr_temp.asm -o mbr_temp.bin
      2⤵
      • Executes dropped EXE
      • System Location Discovery: System Language Discovery
      PID:4852
  • C:\Windows\system32\AUDIODG.EXE
    C:\Windows\system32\AUDIODG.EXE 0x00000000000004F4 0x00000000000004F0
    1⤵
    • Suspicious use of AdjustPrivilegeToken
    PID:4076

Network

        MITRE ATT&CK Enterprise v16

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        mbr_temp.asm

        • Path C:\Users\Admin\AppData\Local\Temp\mbr_temp.asm
        • Size 702B
        • SHA256 7dd19a7ee6898a8081630b30f8f3cb9018e7a8b775559d9b4f25181c483a3bfc
        • MD5 SHA1 SHA512 TLSH

        mbr_temp.bin

        • Path C:\Users\Admin\AppData\Local\Temp\mbr_temp.bin
        • Size 512B
        • SHA256 4a26ce3f89739c4bb3a4272da3e20677417c283ae5e405e85e3ce47ca8542669
        • MD5 SHA1 SHA512 TLSH

        nasm.exe

        • Path C:\Users\Admin\AppData\Local\Temp\nasm.exe
        • Size 1.2MB
        • SHA256 a4735165141570d966b577d594c0541c29baed4978078c1c7237b855f8592a87
        • MD5 SHA1 SHA512 SSDEEP TLSH

        memory/4852-22-0x0000000000400000-0x0000000000539000-memory.dmp

        memory/5288-4-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-5-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-9-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-10-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-11-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-0-0x0000000000340000-0x0000000000682000-memory.dmp

        memory/5288-3-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-2-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-1-0x00007FFDCD7AF000-0x00007FFDCD7B0000-memory.dmp

        memory/5288-27-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-28-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-29-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp

        memory/5288-30-0x00007FFDCD620000-0x00007FFDCDFC4000-memory.dmp