Analysis

  • max time kernel
    149s
  • max time network
    152s
  • platform
    windows11-21h2_x64
  • resource
    win11-20240802-en
  • resource tags

    arch:x64arch:x86image:win11-20240802-enlocale:en-usos:windows11-21h2-x64system
  • submitted
    03/09/2024, 16:53

General

  • Target
    vekvtia.exe
  • Size 10.5MB
  • Sample240903-vefcbasfjb
  • SHA256 21a5e8cf356706a639eee50ea97cecef91685eb906921245c314ac50950b9825
  • 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.

  • 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.

  • Program crash 2 IoCs
  • 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 7 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\vekvtia.exe
    "C:\Users\Admin\AppData\Local\Temp\vekvtia.exe"
    1⤵
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:1964
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\obizrcpk\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:1416
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\ybyrikeu.exe" C:\Windows\SysWOW64\obizrcpk\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:2160
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" create obizrcpk binPath= "C:\Windows\SysWOW64\obizrcpk\ybyrikeu.exe /d\"C:\Users\Admin\AppData\Local\Temp\vekvtia.exe\"" type= own start= auto DisplayName= "wifi support"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:944
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" description obizrcpk "wifi internet conection"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:4936
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" start obizrcpk
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:2644
    • 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:1932
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1964 -s 1216
      2⤵
      • Program crash
      PID:4216
  • C:\Windows\SysWOW64\obizrcpk\ybyrikeu.exe
    C:\Windows\SysWOW64\obizrcpk\ybyrikeu.exe /d"C:\Users\Admin\AppData\Local\Temp\vekvtia.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:4828
    • C:\Windows\SysWOW64\svchost.exe
      svchost.exe
      2⤵
      • 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:132
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 4828 -s 544
      2⤵
      • Program crash
      PID:852
  • C:\Windows\SysWOW64\WerFault.exe
    C:\Windows\SysWOW64\WerFault.exe -pss -s 436 -p 1964 -ip 1964
    1⤵
      PID:2368
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -pss -s 476 -p 4828 -ip 4828
      1⤵
        PID:2060

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

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            Downloads

            ybyrikeu.exe

            • Path C:\Users\Admin\AppData\Local\Temp\ybyrikeu.exe
            • Size 14.6MB
            • SHA256 83dc7a944be536ebd5cdda86381f84235930e36be9fea78504e0a997763ace58
            • MD5 SHA1 SHA512 SSDEEP

            memory/132-36-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-44-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-54-0x0000000008000000-0x000000000840B000-memory.dmp

            memory/132-42-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-9-0x0000000000FB0000-0x0000000000FC5000-memory.dmp

            memory/132-23-0x0000000003080000-0x000000000328F000-memory.dmp

            memory/132-24-0x0000000001D80000-0x0000000001D86000-memory.dmp

            memory/132-27-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-30-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-43-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-17-0x0000000000FB0000-0x0000000000FC5000-memory.dmp

            memory/132-18-0x0000000000FB0000-0x0000000000FC5000-memory.dmp

            memory/132-21-0x0000000003080000-0x000000000328F000-memory.dmp

            memory/132-55-0x0000000001EB0000-0x0000000001EB7000-memory.dmp

            memory/132-51-0x0000000008000000-0x000000000840B000-memory.dmp

            memory/132-50-0x0000000001EA0000-0x0000000001EA5000-memory.dmp

            memory/132-47-0x0000000001EA0000-0x0000000001EA5000-memory.dmp

            memory/132-46-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-31-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-45-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-32-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-41-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-40-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-39-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-38-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-37-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-33-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-35-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/132-34-0x0000000001D90000-0x0000000001DA0000-memory.dmp

            memory/1964-1-0x0000000000710000-0x0000000000810000-memory.dmp

            memory/1964-14-0x0000000000400000-0x00000000005FE000-memory.dmp

            memory/1964-3-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/1964-16-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/1964-15-0x0000000002300000-0x0000000002313000-memory.dmp

            memory/1964-2-0x0000000002300000-0x0000000002313000-memory.dmp

            memory/4828-12-0x0000000000400000-0x00000000005FE000-memory.dmp

            memory/4828-11-0x0000000000400000-0x00000000005FE000-memory.dmp

            memory/4828-8-0x0000000000400000-0x00000000005FE000-memory.dmp