Analysis

  • max time kernel
    150s
  • max time network
    151s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240709-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240709-enlocale:en-usos:windows10-2004-x64system
  • submitted
    09/07/2024, 21:01

General

  • Target
    339abf17eb0f812bf619f2034c9ae48fd5f65a3a419c150f198db6df840fc5ac.exe
  • Size 314KB
  • Sample240709-zvb22sxcnf
  • SHA256 339abf17eb0f812bf619f2034c9ae48fd5f65a3a419c150f198db6df840fc5ac
  • 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
  • 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).

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

Processes

  • C:\Users\Admin\AppData\Local\Temp\339abf17eb0f812bf619f2034c9ae48fd5f65a3a419c150f198db6df840fc5ac.exe
    "C:\Users\Admin\AppData\Local\Temp\339abf17eb0f812bf619f2034c9ae48fd5f65a3a419c150f198db6df840fc5ac.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:4488
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\vagixpou\
      2⤵
        PID:2208
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\ykwbyedr.exe" C:\Windows\SysWOW64\vagixpou\
        2⤵
          PID:4572
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create vagixpou binPath= "C:\Windows\SysWOW64\vagixpou\ykwbyedr.exe /d\"C:\Users\Admin\AppData\Local\Temp\339abf17eb0f812bf619f2034c9ae48fd5f65a3a419c150f198db6df840fc5ac.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:3372
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description vagixpou "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:4716
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start vagixpou
          2⤵
          • Launches sc.exe
          PID:4828
        • 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
          PID:424
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 4488 -s 1272
          2⤵
          • Program crash
          PID:1508
      • C:\Windows\SysWOW64\vagixpou\ykwbyedr.exe
        C:\Windows\SysWOW64\vagixpou\ykwbyedr.exe /d"C:\Users\Admin\AppData\Local\Temp\339abf17eb0f812bf619f2034c9ae48fd5f65a3a419c150f198db6df840fc5ac.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:3604
        • 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:3688
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 3604 -s 544
          2⤵
          • Program crash
          PID:2716
      • C:\Windows\SysWOW64\WerFault.exe
        C:\Windows\SysWOW64\WerFault.exe -pss -s 456 -p 4488 -ip 4488
        1⤵
          PID:428
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 420 -p 3604 -ip 3604
          1⤵
            PID:4872

          Network

                MITRE ATT&CK Enterprise v15

                Replay Monitor

                Loading Replay Monitor...

                Downloads

                ykwbyedr.exe

                • Path C:\Users\Admin\AppData\Local\Temp\ykwbyedr.exe
                • Size 13.3MB
                • SHA256 eb416800dd5124e21ad386b44321f042d6dbb4b86fda2bf664a90001f591fe73
                • MD5 SHA1 SHA512 SSDEEP

                memory/3604-15-0x0000000000400000-0x0000000002836000-memory.dmp

                memory/3688-43-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-41-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-20-0x0000000002400000-0x000000000260F000-memory.dmp

                memory/3688-21-0x0000000000A70000-0x0000000000A76000-memory.dmp

                memory/3688-27-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-11-0x00000000006E0000-0x00000000006F5000-memory.dmp

                memory/3688-13-0x00000000006E0000-0x00000000006F5000-memory.dmp

                memory/3688-14-0x00000000006E0000-0x00000000006F5000-memory.dmp

                memory/3688-28-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-17-0x0000000002400000-0x000000000260F000-memory.dmp

                memory/3688-24-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-52-0x00000000027E0000-0x00000000027E7000-memory.dmp

                memory/3688-48-0x0000000007300000-0x000000000770B000-memory.dmp

                memory/3688-47-0x00000000027D0000-0x00000000027D5000-memory.dmp

                memory/3688-44-0x00000000027D0000-0x00000000027D5000-memory.dmp

                memory/3688-42-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-29-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-30-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-51-0x0000000007300000-0x000000000770B000-memory.dmp

                memory/3688-39-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-40-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-38-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-37-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-36-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-35-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-34-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-33-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-32-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/3688-31-0x0000000000BF0000-0x0000000000C00000-memory.dmp

                memory/4488-1-0x0000000002A50000-0x0000000002B50000-memory.dmp

                memory/4488-4-0x0000000000400000-0x0000000000415000-memory.dmp

                memory/4488-2-0x00000000029E0000-0x00000000029F3000-memory.dmp

                memory/4488-7-0x0000000000400000-0x0000000002836000-memory.dmp

                memory/4488-8-0x00000000029E0000-0x00000000029F3000-memory.dmp

                memory/4488-9-0x0000000000400000-0x0000000000415000-memory.dmp