Analysis

  • max time kernel
    146s
  • max time network
    155s
  • platform
    windows10-1703_x64
  • resource
    win10-20240404-en
  • resource tags

    arch:x64arch:x86image:win10-20240404-enlocale:en-usos:windows10-1703-x64system
  • submitted
    03/09/2024, 16:57

General

  • Target
    ybyrikeu.exe
  • Size 14.6MB
  • Sample240903-vgpzjasfph
  • SHA256 83dc7a944be536ebd5cdda86381f84235930e36be9fea78504e0a997763ace58
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • tofsee

C2
  • vanaheim.cn

  • jotunheim.name

Signatures

  • Tofsee

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

  • Windows security bypass 2 TTPs 1 IoCs
  • Creates new service(s) 2 TTPs
  • Modifies Windows Firewall 2 TTPs 1 IoCs
  • Sets service image path in registry 2 TTPs 1 IoCs
  • Deletes itself 1 IoCs
  • Executes dropped EXE 1 IoCs
  • Drops file in System32 directory 2 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.

  • 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.

  • Modifies data under HKEY_USERS 6 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\ybyrikeu.exe
    "C:\Users\Admin\AppData\Local\Temp\ybyrikeu.exe"
    1⤵
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:840
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\hnxsksvc\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:1152
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\tfnkqdjh.exe" C:\Windows\SysWOW64\hnxsksvc\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:1016
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" create hnxsksvc binPath= "C:\Windows\SysWOW64\hnxsksvc\tfnkqdjh.exe /d\"C:\Users\Admin\AppData\Local\Temp\ybyrikeu.exe\"" type= own start= auto DisplayName= "wifi support"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:2264
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" description hnxsksvc "wifi internet conection"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:4116
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" start hnxsksvc
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:1872
    • 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:2096
  • C:\Windows\SysWOW64\hnxsksvc\tfnkqdjh.exe
    C:\Windows\SysWOW64\hnxsksvc\tfnkqdjh.exe /d"C:\Users\Admin\AppData\Local\Temp\ybyrikeu.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:4660
    • C:\Windows\SysWOW64\svchost.exe
      svchost.exe
      2⤵
      • Windows security bypass
      • Sets service image path in registry
      • Deletes itself
      • Drops file in System32 directory
      • System Location Discovery: System Language Discovery
      • Modifies data under HKEY_USERS
      PID:2288

Network

        MITRE ATT&CK Enterprise v15

        Replay Monitor

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        Downloads

        tfnkqdjh.exe

        • Path C:\Users\Admin\AppData\Local\Temp\tfnkqdjh.exe
        • Size 14.7MB
        • SHA256 3805b686f31987e6369aa344fd41f9cfa965bd510a2283246304a5abf19c9275
        • MD5 SHA1 SHA512 SSDEEP

        memory/840-1-0x0000000000930000-0x0000000000A30000-memory.dmp

        memory/840-2-0x0000000000840000-0x0000000000853000-memory.dmp

        memory/840-3-0x0000000000400000-0x0000000000415000-memory.dmp

        memory/840-7-0x0000000000400000-0x00000000005FE000-memory.dmp

        memory/840-9-0x0000000000400000-0x0000000000415000-memory.dmp

        memory/840-8-0x0000000000840000-0x0000000000853000-memory.dmp

        memory/2288-45-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-41-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-16-0x00000000009A0000-0x00000000009B5000-memory.dmp

        memory/2288-15-0x00000000009A0000-0x00000000009B5000-memory.dmp

        memory/2288-17-0x00000000009A0000-0x00000000009B5000-memory.dmp

        memory/2288-22-0x0000000004740000-0x000000000494F000-memory.dmp

        memory/2288-54-0x0000000000D20000-0x0000000000D27000-memory.dmp

        memory/2288-53-0x0000000008E90000-0x000000000929B000-memory.dmp

        memory/2288-50-0x0000000008E90000-0x000000000929B000-memory.dmp

        memory/2288-49-0x0000000000D10000-0x0000000000D15000-memory.dmp

        memory/2288-46-0x0000000000D10000-0x0000000000D15000-memory.dmp

        memory/2288-11-0x00000000009A0000-0x00000000009B5000-memory.dmp

        memory/2288-44-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-43-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-42-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-20-0x0000000004740000-0x000000000494F000-memory.dmp

        memory/2288-40-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-39-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-38-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-37-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-36-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-35-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-34-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-33-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-32-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-31-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-30-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-29-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-26-0x00000000009E0000-0x00000000009F0000-memory.dmp

        memory/2288-23-0x00000000009D0000-0x00000000009D6000-memory.dmp

        memory/4660-12-0x0000000000400000-0x00000000005FE000-memory.dmp