Analysis

  • max time kernel
    148s
  • max time network
    151s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240226-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240226-enlocale:en-usos:windows10-2004-x64system
  • submitted
    02/04/2024, 10:12

General

  • Target
    cb1c506be26eb65bd7c79abc7e54d356adea2c3e0993e605e98cc39611f7add1.exe
  • Size 242KB
  • Sample240402-l8py6sed7y
  • SHA256 cb1c506be26eb65bd7c79abc7e54d356adea2c3e0993e605e98cc39611f7add1
  • 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
  • Looks up external IP address via web service 1 IoCs

    Uses a legitimate IP lookup service to find the infected system's external IP.

  • 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\cb1c506be26eb65bd7c79abc7e54d356adea2c3e0993e605e98cc39611f7add1.exe
    "C:\Users\Admin\AppData\Local\Temp\cb1c506be26eb65bd7c79abc7e54d356adea2c3e0993e605e98cc39611f7add1.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:3756
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\uamhqwfo\
      2⤵
        PID:228
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\jzvkfxvd.exe" C:\Windows\SysWOW64\uamhqwfo\
        2⤵
          PID:3012
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create uamhqwfo binPath= "C:\Windows\SysWOW64\uamhqwfo\jzvkfxvd.exe /d\"C:\Users\Admin\AppData\Local\Temp\cb1c506be26eb65bd7c79abc7e54d356adea2c3e0993e605e98cc39611f7add1.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:3296
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description uamhqwfo "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:1340
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start uamhqwfo
          2⤵
          • Launches sc.exe
          PID:764
        • 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:2356
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 3756 -s 1036
          2⤵
          • Program crash
          PID:4408
      • C:\Windows\SysWOW64\uamhqwfo\jzvkfxvd.exe
        C:\Windows\SysWOW64\uamhqwfo\jzvkfxvd.exe /d"C:\Users\Admin\AppData\Local\Temp\cb1c506be26eb65bd7c79abc7e54d356adea2c3e0993e605e98cc39611f7add1.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:2648
        • 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:2912
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 2648 -s 512
          2⤵
          • Program crash
          PID:768
      • C:\Windows\SysWOW64\WerFault.exe
        C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 3756 -ip 3756
        1⤵
          PID:3188
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 360 -p 2648 -ip 2648
          1⤵
            PID:2436

          Network

                MITRE ATT&CK Enterprise v15

                Replay Monitor

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                Downloads

                jzvkfxvd.exe

                • Path C:\Users\Admin\AppData\Local\Temp\jzvkfxvd.exe
                • Size 12.4MB
                • SHA256 f34e62f42c64c3aa8ce93fafd31cfebe0b8feb0175eacae39e169607ecff9497
                • MD5 SHA1 SHA512 SSDEEP

                memory/2648-10-0x0000000000B00000-0x0000000000C00000-memory.dmp

                memory/2648-17-0x0000000000400000-0x00000000007C6000-memory.dmp

                memory/2648-12-0x0000000000400000-0x00000000007C6000-memory.dmp

                memory/2912-47-0x00000000035D0000-0x00000000035D5000-memory.dmp

                memory/2912-44-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-59-0x0000000000ED0000-0x0000000000EE5000-memory.dmp

                memory/2912-23-0x0000000002C00000-0x0000000002E0F000-memory.dmp

                memory/2912-11-0x0000000000ED0000-0x0000000000EE5000-memory.dmp

                memory/2912-16-0x0000000000ED0000-0x0000000000EE5000-memory.dmp

                memory/2912-24-0x0000000002380000-0x0000000002386000-memory.dmp

                memory/2912-18-0x0000000000ED0000-0x0000000000EE5000-memory.dmp

                memory/2912-20-0x0000000002C00000-0x0000000002E0F000-memory.dmp

                memory/2912-37-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-51-0x0000000008100000-0x000000000850B000-memory.dmp

                memory/2912-55-0x00000000035E0000-0x00000000035E7000-memory.dmp

                memory/2912-54-0x0000000008100000-0x000000000850B000-memory.dmp

                memory/2912-50-0x00000000035D0000-0x00000000035D5000-memory.dmp

                memory/2912-27-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-46-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-45-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-30-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-43-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-42-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-41-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-40-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-39-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-38-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-36-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-35-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-34-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-33-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-32-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/2912-31-0x0000000002390000-0x00000000023A0000-memory.dmp

                memory/3756-9-0x0000000000A70000-0x0000000000A83000-memory.dmp

                memory/3756-1-0x0000000000AC0000-0x0000000000BC0000-memory.dmp

                memory/3756-2-0x0000000000A70000-0x0000000000A83000-memory.dmp

                memory/3756-4-0x0000000000400000-0x00000000007C6000-memory.dmp

                memory/3756-8-0x0000000000400000-0x00000000007C6000-memory.dmp