Analysis

  • max time kernel
    150s
  • max time network
    157s
  • 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
    c9ba75c3c2b17dd64211ae2d9859ced46f797f4f25d867c63c813462a857b524.exe
  • Size 203KB
  • Sample240402-l8py6seh55
  • SHA256 c9ba75c3c2b17dd64211ae2d9859ced46f797f4f25d867c63c813462a857b524
  • 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\c9ba75c3c2b17dd64211ae2d9859ced46f797f4f25d867c63c813462a857b524.exe
    "C:\Users\Admin\AppData\Local\Temp\c9ba75c3c2b17dd64211ae2d9859ced46f797f4f25d867c63c813462a857b524.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:3004
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\rqgbzdhf\
      2⤵
        PID:4688
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\elkxffnr.exe" C:\Windows\SysWOW64\rqgbzdhf\
        2⤵
          PID:1612
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create rqgbzdhf binPath= "C:\Windows\SysWOW64\rqgbzdhf\elkxffnr.exe /d\"C:\Users\Admin\AppData\Local\Temp\c9ba75c3c2b17dd64211ae2d9859ced46f797f4f25d867c63c813462a857b524.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:3092
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description rqgbzdhf "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:2892
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start rqgbzdhf
          2⤵
          • Launches sc.exe
          PID:5056
        • 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:2692
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 3004 -s 1260
          2⤵
          • Program crash
          PID:4360
      • C:\Windows\SysWOW64\rqgbzdhf\elkxffnr.exe
        C:\Windows\SysWOW64\rqgbzdhf\elkxffnr.exe /d"C:\Users\Admin\AppData\Local\Temp\c9ba75c3c2b17dd64211ae2d9859ced46f797f4f25d867c63c813462a857b524.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:2900
        • 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:1504
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 2900 -s 512
          2⤵
          • Program crash
          PID:3672
      • C:\Windows\SysWOW64\WerFault.exe
        C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 3004 -ip 3004
        1⤵
          PID:4336
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 468 -p 2900 -ip 2900
          1⤵
            PID:2356

          Network

                MITRE ATT&CK Enterprise v15

                Replay Monitor

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                Downloads

                elkxffnr.exe

                • Path C:\Users\Admin\AppData\Local\Temp\elkxffnr.exe
                • Size 14.2MB
                • SHA256 388e79263a845871aa2ef6566ec212ccf8bebd4d8e9c7e2d2ede7bc46dd3fe76
                • MD5 SHA1 SHA512 SSDEEP

                memory/1504-43-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-32-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-59-0x0000000000A70000-0x0000000000A85000-memory.dmp

                memory/1504-55-0x0000000002BE0000-0x0000000002BE7000-memory.dmp

                memory/1504-54-0x0000000007640000-0x0000000007A4B000-memory.dmp

                memory/1504-10-0x0000000000A70000-0x0000000000A85000-memory.dmp

                memory/1504-51-0x0000000007640000-0x0000000007A4B000-memory.dmp

                memory/1504-14-0x0000000000A70000-0x0000000000A85000-memory.dmp

                memory/1504-50-0x0000000002BD0000-0x0000000002BD5000-memory.dmp

                memory/1504-47-0x0000000002BD0000-0x0000000002BD5000-memory.dmp

                memory/1504-17-0x0000000000A70000-0x0000000000A85000-memory.dmp

                memory/1504-18-0x0000000000A70000-0x0000000000A85000-memory.dmp

                memory/1504-20-0x0000000002600000-0x000000000280F000-memory.dmp

                memory/1504-23-0x0000000002600000-0x000000000280F000-memory.dmp

                memory/1504-24-0x0000000001DE0000-0x0000000001DE6000-memory.dmp

                memory/1504-27-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-34-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-30-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-46-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-33-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-37-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-31-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-36-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-35-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-38-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-39-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-40-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-41-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-42-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-45-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/1504-44-0x0000000001DF0000-0x0000000001E00000-memory.dmp

                memory/2900-15-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/2900-9-0x00000000005A0000-0x00000000005B3000-memory.dmp

                memory/2900-11-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/2900-8-0x0000000000600000-0x0000000000700000-memory.dmp

                memory/3004-1-0x0000000000570000-0x0000000000670000-memory.dmp

                memory/3004-3-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/3004-16-0x0000000000400000-0x0000000000438000-memory.dmp

                memory/3004-2-0x0000000000510000-0x0000000000523000-memory.dmp