Analysis

  • max time kernel
    148s
  • max time network
    150s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240419-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240419-enlocale:en-usos:windows10-2004-x64system
  • submitted
    07/05/2024, 09:22

General

  • Target
    5d711364f716a3ca2fc403dc12ba6d19ce33bffdc574723c1ab096f10d482b2f.exe
  • Size 11.5MB
  • Sample240507-lb1peach63
  • SHA256 5d711364f716a3ca2fc403dc12ba6d19ce33bffdc574723c1ab096f10d482b2f
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • tofsee

C2
  • svartalfheim.top

  • 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).

  • Program crash 2 IoCs
  • Modifies data under HKEY_USERS 6 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\5d711364f716a3ca2fc403dc12ba6d19ce33bffdc574723c1ab096f10d482b2f.exe
    "C:\Users\Admin\AppData\Local\Temp\5d711364f716a3ca2fc403dc12ba6d19ce33bffdc574723c1ab096f10d482b2f.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:2484
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\sizfeohh\
      2⤵
        PID:3060
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\yjfkbugv.exe" C:\Windows\SysWOW64\sizfeohh\
        2⤵
          PID:1304
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create sizfeohh binPath= "C:\Windows\SysWOW64\sizfeohh\yjfkbugv.exe /d\"C:\Users\Admin\AppData\Local\Temp\5d711364f716a3ca2fc403dc12ba6d19ce33bffdc574723c1ab096f10d482b2f.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:1300
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description sizfeohh "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:1412
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start sizfeohh
          2⤵
          • Launches sc.exe
          PID:4692
        • 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:3280
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 2484 -s 1236
          2⤵
          • Program crash
          PID:3964
      • C:\Windows\SysWOW64\sizfeohh\yjfkbugv.exe
        C:\Windows\SysWOW64\sizfeohh\yjfkbugv.exe /d"C:\Users\Admin\AppData\Local\Temp\5d711364f716a3ca2fc403dc12ba6d19ce33bffdc574723c1ab096f10d482b2f.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:4524
        • 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:1892
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 4524 -s 540
          2⤵
          • Program crash
          PID:1592
      • C:\Windows\SysWOW64\WerFault.exe
        C:\Windows\SysWOW64\WerFault.exe -pss -s 408 -p 2484 -ip 2484
        1⤵
          PID:2952
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 412 -p 4524 -ip 4524
          1⤵
            PID:1928

          Network

                MITRE ATT&CK Enterprise v15

                Replay Monitor

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                Downloads

                yjfkbugv.exe

                • Path C:\Users\Admin\AppData\Local\Temp\yjfkbugv.exe
                • Size 13.0MB
                • SHA256 2357889152e894a5f64af08fa810e21dcad459529f373ead706b588dbe8aa0bc
                • MD5 SHA1 SHA512 SSDEEP

                memory/1892-42-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-44-0x00000000023F0000-0x00000000023F5000-memory.dmp

                memory/1892-29-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-20-0x0000000002C00000-0x0000000002E0F000-memory.dmp

                memory/1892-21-0x00000000023D0000-0x00000000023D6000-memory.dmp

                memory/1892-27-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-11-0x0000000000D20000-0x0000000000D35000-memory.dmp

                memory/1892-13-0x0000000000D20000-0x0000000000D35000-memory.dmp

                memory/1892-14-0x0000000000D20000-0x0000000000D35000-memory.dmp

                memory/1892-28-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-17-0x0000000002C00000-0x0000000002E0F000-memory.dmp

                memory/1892-24-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-52-0x00000000031D0000-0x00000000031D7000-memory.dmp

                memory/1892-48-0x0000000007C40000-0x000000000804B000-memory.dmp

                memory/1892-47-0x00000000023F0000-0x00000000023F5000-memory.dmp

                memory/1892-51-0x0000000007C40000-0x000000000804B000-memory.dmp

                memory/1892-30-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-43-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-31-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-40-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-39-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-38-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-37-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-36-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-35-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-34-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-33-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-32-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/1892-41-0x00000000023E0000-0x00000000023F0000-memory.dmp

                memory/2484-4-0x0000000000400000-0x0000000000415000-memory.dmp

                memory/2484-1-0x0000000002D50000-0x0000000002E50000-memory.dmp

                memory/2484-8-0x0000000000400000-0x0000000002C2E000-memory.dmp

                memory/2484-9-0x0000000002D10000-0x0000000002D23000-memory.dmp

                memory/2484-10-0x0000000000400000-0x0000000000415000-memory.dmp

                memory/2484-2-0x0000000002D10000-0x0000000002D23000-memory.dmp

                memory/4524-15-0x0000000000400000-0x0000000002C2E000-memory.dmp