Analysis

  • max time kernel
    148s
  • max time network
    146s
  • platform
    windows11-ltsc_2024_x64
  • resource
    win11ltsc2024-20260911-en
  • resource tags

    arch:x64arch:x86image:win11ltsc2024-20260911-enlocale:en-usos:windows11-ltsc_2024-x64systemwindows
  • submitted
    10/10/2026, 13:18

General

  • Target
    f8136b8811cee0bb772ab3a2427dc2942781f94c9eea5f0de9e8a798b3793301.exe
  • Size 11.7MB
  • Sample261010-qjw4eavycv
  • SHA256 f8136b8811cee0bb772ab3a2427dc2942781f94c9eea5f0de9e8a798b3793301
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Extracted

Family
  • tofsee

C2
  • vanaheim.cn

  • jotunheim.name

Signatures

  • Family: Tofsee

    Backdoor/botnet which carries out malicious activities based on commands from a C2 server.

  • Windows security bypass 2 TTPs 1 IoCs
  • Modifies Windows Firewall 2 TTPs 1 IoCs
  • Sets service image path in registry 3 TTPs 1 IoCs

    This determines the executable launched when a service starts. It can be used to establish persistence.

  • Creates new service(s) 2 TTPs
  • Deletes itself 1 TTPs 1 IoCs
  • Executes dropped EXE 1 IoCs
  • Suspicious use of SetThreadContext 1 IoCs
  • Launches sc.exe 3 IoCs

    Sc.exe is a Windows utlilty to control services on the system.

  • Enumerates physical storage devices 1 TTPs

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

  • Event Triggered Execution: Netsh Helper DLL 1 TTPs 3 IoCs

    Netsh.exe (also referred to as Netshell) is a command-line scripting utility used to interact with the network configuration of a system.

  • Executes a command shell one-liner 1 TTPs 2 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 9 IoCs

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

  • Suspicious use of WriteProcessMemory 8 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\f8136b8811cee0bb772ab3a2427dc2942781f94c9eea5f0de9e8a798b3793301.exe
    "C:\Users\Admin\AppData\Local\Temp\f8136b8811cee0bb772ab3a2427dc2942781f94c9eea5f0de9e8a798b3793301.exe"
    1⤵
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:952
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\ncnxnvki\
      2⤵
      • Executes a command shell one-liner
      • System Location Discovery: System Language Discovery
      PID:1800
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\vyvofhbr.exe" C:\Windows\SysWOW64\ncnxnvki\
      2⤵
      • Executes a command shell one-liner
      • System Location Discovery: System Language Discovery
      PID:5228
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" create ncnxnvki binPath= "C:\Windows\SysWOW64\ncnxnvki\vyvofhbr.exe /d\"C:\Users\Admin\AppData\Local\Temp\f8136b8811cee0bb772ab3a2427dc2942781f94c9eea5f0de9e8a798b3793301.exe\"" type= own start= auto DisplayName= "wifi support"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:5092
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" description ncnxnvki "wifi internet conection"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:4200
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" start ncnxnvki
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:704
    • C:\Windows\SysWOW64\netsh.exe
      "C:\Windows\System32\netsh.exe" advfirewall firewall add rule name="Host-process for services of Windows" dir=in action=allow program="C:\Windows\SysWOW64\svchost.exe" enable=yes>nul
      2⤵
      • Modifies Windows Firewall
      • Event Triggered Execution: Netsh Helper DLL
      • System Location Discovery: System Language Discovery
      PID:1200
  • C:\Windows\SysWOW64\ncnxnvki\vyvofhbr.exe
    C:\Windows\SysWOW64\ncnxnvki\vyvofhbr.exe /d"C:\Users\Admin\AppData\Local\Temp\f8136b8811cee0bb772ab3a2427dc2942781f94c9eea5f0de9e8a798b3793301.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:5812
    • C:\Windows\SysWOW64\svchost.exe
      svchost.exe
      2⤵
      • Windows security bypass
      • Sets service image path in registry
      • Deletes itself
      • System Location Discovery: System Language Discovery
      PID:1104

Network

        MITRE ATT&CK Enterprise v16

        Replay Monitor

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        Downloads

        vyvofhbr.exe

        • Path C:\Users\Admin\AppData\Local\Temp\vyvofhbr.exe
        • Size 10.7MB
        • SHA256 21d08ebdc792eddd05a45c242e36e69c9562727a69c008812ee61f10574bf121
        • MD5 SHA1 SHA512 SSDEEP TLSH

        memory/1104-4-0x0000000000C40000-0x0000000000C55000-memory.dmp

        memory/1104-7-0x0000000000C40000-0x0000000000C55000-memory.dmp

        memory/1104-8-0x0000000000C40000-0x0000000000C55000-memory.dmp

        memory/1104-9-0x0000000000C40000-0x0000000000C55000-memory.dmp

        memory/1104-10-0x0000000000C40000-0x0000000000C55000-memory.dmp