Analysis

  • max time kernel
    147s
  • max time network
    152s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240412-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240412-enlocale:en-usos:windows10-2004-x64system
  • submitted
    17/04/2024, 14:50

General

  • Target
    8240e21305559cabc41ccf60e6683e8fb3f6ae80a20e289e687366ccc4594c40.exe
  • Size 203KB
  • Sample240417-r7nmlsec7t
  • SHA256 8240e21305559cabc41ccf60e6683e8fb3f6ae80a20e289e687366ccc4594c40
  • 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) 1 TTPs
  • Modifies Windows Firewall 2 TTPs 1 IoCs
  • Sets service image path in registry 2 TTPs 1 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

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

  • 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).

  • Program crash 2 IoCs
  • Modifies data under HKEY_USERS 7 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\8240e21305559cabc41ccf60e6683e8fb3f6ae80a20e289e687366ccc4594c40.exe
    "C:\Users\Admin\AppData\Local\Temp\8240e21305559cabc41ccf60e6683e8fb3f6ae80a20e289e687366ccc4594c40.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:1948
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\wuzbhmbt\
      2⤵
        PID:2516
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\vlhwrjhp.exe" C:\Windows\SysWOW64\wuzbhmbt\
        2⤵
          PID:3316
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create wuzbhmbt binPath= "C:\Windows\SysWOW64\wuzbhmbt\vlhwrjhp.exe /d\"C:\Users\Admin\AppData\Local\Temp\8240e21305559cabc41ccf60e6683e8fb3f6ae80a20e289e687366ccc4594c40.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:1032
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description wuzbhmbt "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:1240
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start wuzbhmbt
          2⤵
          • Launches sc.exe
          PID:1108
        • 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
          PID:3856
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 1948 -s 1040
          2⤵
          • Program crash
          PID:3548
      • C:\Windows\SysWOW64\wuzbhmbt\vlhwrjhp.exe
        C:\Windows\SysWOW64\wuzbhmbt\vlhwrjhp.exe /d"C:\Users\Admin\AppData\Local\Temp\8240e21305559cabc41ccf60e6683e8fb3f6ae80a20e289e687366ccc4594c40.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:1704
        • C:\Windows\SysWOW64\svchost.exe
          svchost.exe
          2⤵
          • Sets service image path in registry
          • Deletes itself
          • Drops file in System32 directory
          • Modifies data under HKEY_USERS
          PID:3132
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 1704 -s 524
          2⤵
          • Program crash
          PID:4508
      • C:\Windows\SysWOW64\WerFault.exe
        C:\Windows\SysWOW64\WerFault.exe -pss -s 468 -p 1948 -ip 1948
        1⤵
          PID:3956
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 508 -p 1704 -ip 1704
          1⤵
            PID:2724

          Network

                MITRE ATT&CK Enterprise v15

                Replay Monitor

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                Downloads

                vlhwrjhp.exe

                • Path C:\Users\Admin\AppData\Local\Temp\vlhwrjhp.exe
                • Size 14.6MB
                • SHA256 fd1e77ab44d6df433a69cf9810cf908a4fddac7c886e0aad7f52915fa8d897b1
                • MD5 SHA1 SHA512 SSDEEP

                memory/1704-8-0x0000000000490000-0x0000000000590000-memory.dmp

                memory/1704-9-0x00000000005C0000-0x00000000005D3000-memory.dmp

                memory/1704-10-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/1704-16-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/1948-15-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/1948-2-0x0000000002180000-0x0000000002193000-memory.dmp

                memory/1948-3-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/1948-1-0x0000000000670000-0x0000000000770000-memory.dmp

                memory/3132-51-0x0000000007550000-0x000000000795B000-memory.dmp

                memory/3132-55-0x0000000007AA0000-0x0000000007AA7000-memory.dmp

                memory/3132-17-0x0000000000830000-0x0000000000845000-memory.dmp

                memory/3132-18-0x0000000000830000-0x0000000000845000-memory.dmp

                memory/3132-20-0x0000000002400000-0x000000000260F000-memory.dmp

                memory/3132-23-0x0000000002400000-0x000000000260F000-memory.dmp

                memory/3132-24-0x00000000009C0000-0x00000000009C6000-memory.dmp

                memory/3132-27-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-34-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-33-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-46-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-11-0x0000000000830000-0x0000000000845000-memory.dmp

                memory/3132-50-0x0000000007400000-0x0000000007405000-memory.dmp

                memory/3132-47-0x0000000007400000-0x0000000007405000-memory.dmp

                memory/3132-45-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-14-0x0000000000830000-0x0000000000845000-memory.dmp

                memory/3132-54-0x0000000007550000-0x000000000795B000-memory.dmp

                memory/3132-44-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-43-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-42-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-41-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-40-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-39-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-37-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-38-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-36-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-35-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-32-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-31-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-30-0x0000000002710000-0x0000000002720000-memory.dmp

                memory/3132-59-0x0000000000830000-0x0000000000845000-memory.dmp