Analysis

  • max time kernel
    116s
  • max time network
    121s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240802-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240802-enlocale:en-usos:windows10-2004-x64system
  • submitted
    14/09/2024, 11:33

General

  • Target
    95b628b19f244451d5f69a864e24b260N.exe
  • Size 379KB
  • Sample240914-nn6sassckd
  • SHA256 c36fbe6dd8f9632176f3927fca2c2e674a5929d33e7d245f1053bf69ec2b11a9
  • 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 6 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\95b628b19f244451d5f69a864e24b260N.exe
    "C:\Users\Admin\AppData\Local\Temp\95b628b19f244451d5f69a864e24b260N.exe"
    1⤵
    • Checks computer location settings
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:344
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\mibocffh\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:4204
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\krybqexh.exe" C:\Windows\SysWOW64\mibocffh\
      2⤵
      • System Location Discovery: System Language Discovery
      PID:4244
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" create mibocffh binPath= "C:\Windows\SysWOW64\mibocffh\krybqexh.exe /d\"C:\Users\Admin\AppData\Local\Temp\95b628b19f244451d5f69a864e24b260N.exe\"" type= own start= auto DisplayName= "wifi support"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:4908
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" description mibocffh "wifi internet conection"
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:772
    • C:\Windows\SysWOW64\sc.exe
      "C:\Windows\System32\sc.exe" start mibocffh
      2⤵
      • Launches sc.exe
      • System Location Discovery: System Language Discovery
      PID:2580
    • 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:4796
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 344 -s 1220
      2⤵
      • Program crash
      PID:4148
  • C:\Windows\SysWOW64\mibocffh\krybqexh.exe
    C:\Windows\SysWOW64\mibocffh\krybqexh.exe /d"C:\Users\Admin\AppData\Local\Temp\95b628b19f244451d5f69a864e24b260N.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of SetThreadContext
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:2840
    • 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:1264
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 2840 -s 528
      2⤵
      • Program crash
      PID:2104
  • C:\Windows\SysWOW64\WerFault.exe
    C:\Windows\SysWOW64\WerFault.exe -pss -s 420 -p 344 -ip 344
    1⤵
      PID:4980
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -pss -s 424 -p 2840 -ip 2840
      1⤵
        PID:2832

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

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            Downloads

            krybqexh.exe

            • Path C:\Users\Admin\AppData\Local\Temp\krybqexh.exe
            • Size 11.7MB
            • SHA256 44dc869343e5dc1783dea7cf2ac018fcda60abf68d6f86e980bd836331b8ca59
            • MD5 SHA1 SHA512 SSDEEP

            memory/344-1-0x0000000002610000-0x0000000002710000-memory.dmp

            memory/344-2-0x00000000041B0000-0x00000000041C3000-memory.dmp

            memory/344-3-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/344-9-0x0000000000400000-0x0000000000415000-memory.dmp

            memory/344-8-0x00000000041B0000-0x00000000041C3000-memory.dmp

            memory/344-7-0x0000000000400000-0x0000000002477000-memory.dmp

            memory/1264-43-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-39-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-14-0x0000000000180000-0x0000000000195000-memory.dmp

            memory/1264-51-0x0000000006F80000-0x000000000738B000-memory.dmp

            memory/1264-38-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-28-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-17-0x0000000002000000-0x000000000220F000-memory.dmp

            memory/1264-21-0x0000000000AF0000-0x0000000000AF6000-memory.dmp

            memory/1264-48-0x0000000006F80000-0x000000000738B000-memory.dmp

            memory/1264-47-0x00000000017D0000-0x00000000017D5000-memory.dmp

            memory/1264-44-0x00000000017D0000-0x00000000017D5000-memory.dmp

            memory/1264-11-0x0000000000180000-0x0000000000195000-memory.dmp

            memory/1264-42-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-41-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-40-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-13-0x0000000000180000-0x0000000000195000-memory.dmp

            memory/1264-37-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-36-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-35-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-34-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-33-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-32-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-31-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-30-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-29-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-27-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-24-0x0000000001740000-0x0000000001750000-memory.dmp

            memory/1264-20-0x0000000002000000-0x000000000220F000-memory.dmp

            memory/1264-52-0x00000000017E0000-0x00000000017E7000-memory.dmp

            memory/2840-15-0x0000000000400000-0x0000000002477000-memory.dmp