Analysis

  • max time kernel
    119s
  • max time network
    120s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240709-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240709-enlocale:en-usos:windows10-2004-x64system
  • submitted
    24/07/2024, 02:59

General

  • Target
    3ecc563f2db24ced9f0138f853b94a80N.exe
  • Size 286KB
  • Sample240724-dgr1fsvbmj
  • SHA256 faa8a428970f1cee3be449e33cb2a03cea27c976dada0bbd8aace22241a2f7f9
  • 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
  • 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 6 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\3ecc563f2db24ced9f0138f853b94a80N.exe
    "C:\Users\Admin\AppData\Local\Temp\3ecc563f2db24ced9f0138f853b94a80N.exe"
    1⤵
    • Checks computer location settings
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:1000
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\nuuvrxmc\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:3768
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\iukxlkcg.exe" C:\Windows\SysWOW64\nuuvrxmc\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:4196
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" create nuuvrxmc binPath= "C:\Windows\SysWOW64\nuuvrxmc\iukxlkcg.exe /d\"C:\Users\Admin\AppData\Local\Temp\3ecc563f2db24ced9f0138f853b94a80N.exe\"" type= own start= auto DisplayName= "wifi support"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:4484
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" description nuuvrxmc "wifi internet conection"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:3496
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" start nuuvrxmc
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:3644
    • 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:1592
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1000 -s 1044
      2⤵
      • Program crash
      PID:2228
  • C:\Windows\SysWOW64\nuuvrxmc\iukxlkcg.exe
    C:\Windows\SysWOW64\nuuvrxmc\iukxlkcg.exe /d"C:\Users\Admin\AppData\Local\Temp\3ecc563f2db24ced9f0138f853b94a80N.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:2220
    • 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:4664
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 2220 -s 508
      2⤵
      • Program crash
      PID:3956
  • C:\Windows\SysWOW64\WerFault.exe
    C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 1000 -ip 1000
    1⤵
      PID:2136
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -pss -s 416 -p 2220 -ip 2220
      1⤵
        PID:2232

      Network

            MITRE ATT&CK Enterprise v15

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            Downloads

            iukxlkcg.exe

            • Path C:\Users\Admin\AppData\Local\Temp\iukxlkcg.exe
            • Size 13.5MB
            • SHA256 7b8d9b10f5229701e53d9ac16a6415de6a4c6354e8a106f3e2af71eb693deb04
            • MD5 SHA1 SHA512 SSDEEP

            memory/1000-2-0x0000000002620000-0x0000000002633000-memory.dmp

            memory/1000-4-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/1000-9-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/1000-8-0x0000000002620000-0x0000000002633000-memory.dmp

            memory/1000-7-0x0000000000400000-0x0000000002460000-memory.dmp

            memory/1000-1-0x00000000024F0000-0x00000000025F0000-memory.dmp

            memory/2220-15-0x0000000000400000-0x0000000002460000-memory.dmp

            memory/4664-34-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-29-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-11-0x00000000006D0000-0x00000000006E5000-memory.dmp

            memory/4664-17-0x0000000002400000-0x000000000260F000-memory.dmp

            memory/4664-24-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-21-0x0000000000BF0000-0x0000000000BF6000-memory.dmp

            memory/4664-20-0x0000000002400000-0x000000000260F000-memory.dmp

            memory/4664-27-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-47-0x0000000001BF0000-0x0000000001BF5000-memory.dmp

            memory/4664-35-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-13-0x00000000006D0000-0x00000000006E5000-memory.dmp

            memory/4664-33-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-32-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-31-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-30-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-14-0x00000000006D0000-0x00000000006E5000-memory.dmp

            memory/4664-28-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-44-0x0000000001BF0000-0x0000000001BF5000-memory.dmp

            memory/4664-43-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-42-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-41-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-40-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-39-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-38-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-37-0x0000000001BA0000-0x0000000001BB0000-memory.dmp

            memory/4664-52-0x00000000027D0000-0x00000000027D7000-memory.dmp

            memory/4664-51-0x0000000007300000-0x000000000770B000-memory.dmp

            memory/4664-48-0x0000000007300000-0x000000000770B000-memory.dmp

            memory/4664-36-0x0000000001BA0000-0x0000000001BB0000-memory.dmp