Analysis

  • max time kernel
    148s
  • max time network
    148s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240802-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240802-enlocale:en-usos:windows10-2004-x64system
  • submitted
    02/09/2024, 14:57

General

  • Target
    bEsOrli29K.exe
  • Size 213KB
  • Sample240902-sblc2ssgjj
  • SHA256 02c6f9163a5d988cee3ab12c11e03b18329c26d6b4863004f943133654693e97
  • 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 7 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\bEsOrli29K.exe
    "C:\Users\Admin\AppData\Local\Temp\bEsOrli29K.exe"
    1⤵
    • Checks computer location settings
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:2356
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\mtaevnpi\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:1268
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\aphotrwo.exe" C:\Windows\SysWOW64\mtaevnpi\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:932
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" create mtaevnpi binPath= "C:\Windows\SysWOW64\mtaevnpi\aphotrwo.exe /d\"C:\Users\Admin\AppData\Local\Temp\bEsOrli29K.exe\"" type= own start= auto DisplayName= "wifi support"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:4548
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" description mtaevnpi "wifi internet conection"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:4932
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" start mtaevnpi
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:216
    • 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:3416
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 2356 -s 1044
      2⤵
      • Program crash
      PID:4528
  • C:\Windows\SysWOW64\mtaevnpi\aphotrwo.exe
    C:\Windows\SysWOW64\mtaevnpi\aphotrwo.exe /d"C:\Users\Admin\AppData\Local\Temp\bEsOrli29K.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:3136
    • 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:744
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 3136 -s 520
      2⤵
      • Program crash
      PID:4784
  • C:\Windows\SysWOW64\WerFault.exe
    C:\Windows\SysWOW64\WerFault.exe -pss -s 452 -p 2356 -ip 2356
    1⤵
      PID:868
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -pss -s 424 -p 3136 -ip 3136
      1⤵
        PID:876

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

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            Downloads

            aphotrwo.exe

            • Path C:\Users\Admin\AppData\Local\Temp\aphotrwo.exe
            • Size 11.1MB
            • SHA256 f13a90453544db067971114ae52c1c384f3722e849f3b44c4442f48a9e6cc03a
            • MD5 SHA1 SHA512 SSDEEP

            memory/744-45-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-50-0x0000000001FF0000-0x0000000001FF5000-memory.dmp

            memory/744-20-0x0000000002800000-0x0000000002A0F000-memory.dmp

            memory/744-32-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-34-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-54-0x0000000007740000-0x0000000007B4B000-memory.dmp

            memory/744-23-0x0000000002800000-0x0000000002A0F000-memory.dmp

            memory/744-24-0x0000000001F10000-0x0000000001F16000-memory.dmp

            memory/744-27-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-14-0x0000000000960000-0x0000000000975000-memory.dmp

            memory/744-16-0x0000000000960000-0x0000000000975000-memory.dmp

            memory/744-17-0x0000000000960000-0x0000000000975000-memory.dmp

            memory/744-30-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-43-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-51-0x0000000007740000-0x0000000007B4B000-memory.dmp

            memory/744-55-0x0000000002DD0000-0x0000000002DD7000-memory.dmp

            memory/744-31-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-47-0x0000000001FF0000-0x0000000001FF5000-memory.dmp

            memory/744-33-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-46-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-40-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-42-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-41-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-44-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-39-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-38-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-37-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-36-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/744-35-0x0000000001F20000-0x0000000001F30000-memory.dmp

            memory/2356-3-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/2356-1-0x00000000004D0000-0x00000000005D0000-memory.dmp

            memory/2356-8-0x0000000002190000-0x00000000021A3000-memory.dmp

            memory/2356-9-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/2356-7-0x0000000000400000-0x0000000000448000-memory.dmp

            memory/2356-2-0x0000000002190000-0x00000000021A3000-memory.dmp

            memory/3136-18-0x0000000000400000-0x0000000000448000-memory.dmp

            memory/3136-13-0x0000000000400000-0x0000000000448000-memory.dmp

            memory/3136-11-0x0000000000400000-0x0000000000448000-memory.dmp

            memory/3136-12-0x0000000000400000-0x0000000000448000-memory.dmp