Analysis

  • max time kernel
    148s
  • max time network
    152s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240426-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240426-enlocale:en-usos:windows10-2004-x64system
  • submitted
    22/05/2024, 01:58

General

  • Target
    8eb33da353d3756d8cd4cb9308fd5ef72a9b35441bec41fd17c3f3ee508ea9ab.exe
  • Size 204KB
  • Sample240522-cdxk4agh6v
  • SHA256 8eb33da353d3756d8cd4cb9308fd5ef72a9b35441bec41fd17c3f3ee508ea9ab
  • 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).

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

Processes

  • C:\Users\Admin\AppData\Local\Temp\8eb33da353d3756d8cd4cb9308fd5ef72a9b35441bec41fd17c3f3ee508ea9ab.exe
    "C:\Users\Admin\AppData\Local\Temp\8eb33da353d3756d8cd4cb9308fd5ef72a9b35441bec41fd17c3f3ee508ea9ab.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:3324
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\twsyvmko\
      2⤵
        PID:2216
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\bzowpfaw.exe" C:\Windows\SysWOW64\twsyvmko\
        2⤵
          PID:1796
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create twsyvmko binPath= "C:\Windows\SysWOW64\twsyvmko\bzowpfaw.exe /d\"C:\Users\Admin\AppData\Local\Temp\8eb33da353d3756d8cd4cb9308fd5ef72a9b35441bec41fd17c3f3ee508ea9ab.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:2116
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description twsyvmko "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:4320
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start twsyvmko
          2⤵
          • Launches sc.exe
          PID:2000
        • 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:3056
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 3324 -s 1288
          2⤵
          • Program crash
          PID:840
      • C:\Windows\SysWOW64\twsyvmko\bzowpfaw.exe
        C:\Windows\SysWOW64\twsyvmko\bzowpfaw.exe /d"C:\Users\Admin\AppData\Local\Temp\8eb33da353d3756d8cd4cb9308fd5ef72a9b35441bec41fd17c3f3ee508ea9ab.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:768
        • 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:5000
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 768 -s 516
          2⤵
          • Program crash
          PID:2688
      • C:\Windows\SysWOW64\WerFault.exe
        C:\Windows\SysWOW64\WerFault.exe -pss -s 460 -p 3324 -ip 3324
        1⤵
          PID:3596
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 468 -p 768 -ip 768
          1⤵
            PID:1660

          Network

                MITRE ATT&CK Enterprise v15

                Replay Monitor

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                Downloads

                bzowpfaw.exe

                • Path C:\Users\Admin\AppData\Local\Temp\bzowpfaw.exe
                • Size 11.3MB
                • SHA256 2092f985e25e18f975c44e3e59ec90b2b10334bfc05635f9c38046cb8fd754fc
                • MD5 SHA1 SHA512 SSDEEP

                memory/768-9-0x0000000000400000-0x000000000047D000-memory.dmp

                memory/768-10-0x0000000000400000-0x000000000047D000-memory.dmp

                memory/768-8-0x0000000000400000-0x000000000047D000-memory.dmp

                memory/768-16-0x0000000000400000-0x000000000047D000-memory.dmp

                memory/3324-19-0x0000000000400000-0x0000000000415000-memory.dmp

                memory/3324-1-0x00000000004C0000-0x00000000005C0000-memory.dmp

                memory/3324-3-0x0000000000400000-0x0000000000415000-memory.dmp

                memory/3324-2-0x0000000002080000-0x0000000002093000-memory.dmp

                memory/3324-18-0x0000000002080000-0x0000000002093000-memory.dmp

                memory/3324-17-0x0000000000400000-0x000000000047D000-memory.dmp

                memory/5000-49-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-43-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-20-0x00000000012B0000-0x00000000012C5000-memory.dmp

                memory/5000-21-0x00000000012B0000-0x00000000012C5000-memory.dmp

                memory/5000-36-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-58-0x00000000033E0000-0x00000000033E7000-memory.dmp

                memory/5000-54-0x0000000007E80000-0x000000000828B000-memory.dmp

                memory/5000-53-0x00000000033D0000-0x00000000033D5000-memory.dmp

                memory/5000-50-0x00000000033D0000-0x00000000033D5000-memory.dmp

                memory/5000-11-0x00000000012B0000-0x00000000012C5000-memory.dmp

                memory/5000-48-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-47-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-46-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-45-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-44-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-14-0x00000000012B0000-0x00000000012C5000-memory.dmp

                memory/5000-42-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-41-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-40-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-39-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-38-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-37-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-35-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-34-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-33-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-30-0x0000000002770000-0x0000000002780000-memory.dmp

                memory/5000-26-0x0000000003000000-0x000000000320F000-memory.dmp

                memory/5000-57-0x0000000007E80000-0x000000000828B000-memory.dmp

                memory/5000-24-0x0000000003000000-0x000000000320F000-memory.dmp

                memory/5000-27-0x0000000002760000-0x0000000002766000-memory.dmp

                memory/5000-62-0x00000000012B0000-0x00000000012C5000-memory.dmp