Analysis

  • max time kernel
    150s
  • max time network
    164s
  • 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
    900f15042c99288aef15c9187640b625ffec568147dd761f1508e9b61cc174d7.exe
  • Size 204KB
  • Sample240402-l8l8aaeh46
  • SHA256 900f15042c99288aef15c9187640b625ffec568147dd761f1508e9b61cc174d7
  • 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\900f15042c99288aef15c9187640b625ffec568147dd761f1508e9b61cc174d7.exe
    "C:\Users\Admin\AppData\Local\Temp\900f15042c99288aef15c9187640b625ffec568147dd761f1508e9b61cc174d7.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:4972
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\kgzeldui\
      2⤵
        PID:1552
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\tnnfiswi.exe" C:\Windows\SysWOW64\kgzeldui\
        2⤵
          PID:3948
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create kgzeldui binPath= "C:\Windows\SysWOW64\kgzeldui\tnnfiswi.exe /d\"C:\Users\Admin\AppData\Local\Temp\900f15042c99288aef15c9187640b625ffec568147dd761f1508e9b61cc174d7.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:1084
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description kgzeldui "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:2584
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start kgzeldui
          2⤵
          • Launches sc.exe
          PID:4648
        • 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:4788
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 4972 -s 1032
          2⤵
          • Program crash
          PID:5056
      • C:\Windows\SysWOW64\kgzeldui\tnnfiswi.exe
        C:\Windows\SysWOW64\kgzeldui\tnnfiswi.exe /d"C:\Users\Admin\AppData\Local\Temp\900f15042c99288aef15c9187640b625ffec568147dd761f1508e9b61cc174d7.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:5088
        • 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:4352
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 5088 -s 508
          2⤵
          • Program crash
          PID:728
      • C:\Windows\SysWOW64\WerFault.exe
        C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 4972 -ip 4972
        1⤵
          PID:3856
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 488 -p 5088 -ip 5088
          1⤵
            PID:2344

          Network

                MITRE ATT&CK Enterprise v15

                Replay Monitor

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                Downloads

                tnnfiswi.exe

                • Path C:\Users\Admin\AppData\Local\Temp\tnnfiswi.exe
                • Size 10.0MB
                • SHA256 7bbc265836e8c979bce40c1c6f07399a28c4046a7b691d4aab41cf13fece46b7
                • MD5 SHA1 SHA512 SSDEEP

                memory/4352-55-0x00000000027E0000-0x00000000027E7000-memory.dmp

                memory/4352-51-0x0000000007140000-0x000000000754B000-memory.dmp

                memory/4352-59-0x0000000000360000-0x0000000000375000-memory.dmp

                memory/4352-30-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-31-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-9-0x0000000000360000-0x0000000000375000-memory.dmp

                memory/4352-14-0x0000000000360000-0x0000000000375000-memory.dmp

                memory/4352-32-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-33-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-47-0x00000000027D0000-0x00000000027D5000-memory.dmp

                memory/4352-18-0x0000000000360000-0x0000000000375000-memory.dmp

                memory/4352-20-0x0000000002200000-0x000000000240F000-memory.dmp

                memory/4352-23-0x0000000002200000-0x000000000240F000-memory.dmp

                memory/4352-24-0x0000000001920000-0x0000000001926000-memory.dmp

                memory/4352-27-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-37-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-36-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-41-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-34-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-50-0x00000000027D0000-0x00000000027D5000-memory.dmp

                memory/4352-17-0x0000000000360000-0x0000000000375000-memory.dmp

                memory/4352-46-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-45-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-44-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-43-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-54-0x0000000007140000-0x000000000754B000-memory.dmp

                memory/4352-35-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-42-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-40-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-39-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4352-38-0x0000000001930000-0x0000000001940000-memory.dmp

                memory/4972-3-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/4972-1-0x0000000000550000-0x0000000000650000-memory.dmp

                memory/4972-16-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/4972-2-0x0000000002040000-0x0000000002053000-memory.dmp

                memory/5088-8-0x0000000000750000-0x0000000000850000-memory.dmp

                memory/5088-11-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/5088-10-0x0000000000550000-0x0000000000563000-memory.dmp