Analysis

  • max time kernel
    186s
  • max time network
    221s
  • platform
    windows7_x64
  • resource
    win7-en-20211208
  • submitted
    20-02-2022 06:14

General

  • Target

    6a9de64813c2e3ad3940f2b5018245bed83bb0e24a6e47c8b0a4114be7aef623.exe

  • Size

    121KB

  • MD5

    b003a727c9c2e8bec5c17f849c816726

  • SHA1

    23aabb8ab9aa4dfaa55afd29fd09487254b49dff

  • SHA256

    6a9de64813c2e3ad3940f2b5018245bed83bb0e24a6e47c8b0a4114be7aef623

  • SHA512

    21b79ec4c8a1453bfb5c3fbea7d50b6c69be80dfe0413603ad7643c988821d9ecdd19c49608178958e78d41386e841104fcd58cb32e7ca9ffd203a51a2adc271

Malware Config

Extracted

Path

C:\users\Public\RyukReadMe.html

Family

ryuk

Ransom Note
contact balance of shadow universe Ryuk $password = 'dc75X5tp'; $torlink = 'http://oc6mkf4efqrjp2ue6qp6vmz4ofyjmlo6dtqiklqb2q546bnqeu66tbyd.onion'; function info(){alert("INSTRUCTION:\r\n1. Download tor browser.\r\n2. Open link through tor browser: " + $torlink + "\r\n3. Fill the form, your password: "+ $password +"\r\nWe will contact you shortly.\r\nAlways send files for test decryption.");};
URLs

http://oc6mkf4efqrjp2ue6qp6vmz4ofyjmlo6dtqiklqb2q546bnqeu66tbyd.onion

Signatures

  • Ryuk

    Ransomware distributed via existing botnets, often Trickbot or Emotet.

  • Executes dropped EXE 3 IoCs
  • Loads dropped DLL 6 IoCs
  • Modifies file permissions 1 TTPs 2 IoCs
  • Drops file in Program Files directory 64 IoCs
  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

  • Runs net.exe
  • Suspicious behavior: EnumeratesProcesses 11 IoCs
  • Suspicious use of WriteProcessMemory 52 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\6a9de64813c2e3ad3940f2b5018245bed83bb0e24a6e47c8b0a4114be7aef623.exe
    "C:\Users\Admin\AppData\Local\Temp\6a9de64813c2e3ad3940f2b5018245bed83bb0e24a6e47c8b0a4114be7aef623.exe"
    1⤵
    • Loads dropped DLL
    • Drops file in Program Files directory
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    PID:1664
    • C:\Users\Admin\AppData\Local\Temp\HrIEuiIPErep.exe
      "C:\Users\Admin\AppData\Local\Temp\HrIEuiIPErep.exe" 9 REP
      2⤵
      • Executes dropped EXE
      PID:1368
    • C:\Users\Admin\AppData\Local\Temp\voTZRquyulan.exe
      "C:\Users\Admin\AppData\Local\Temp\voTZRquyulan.exe" 8 LAN
      2⤵
      • Executes dropped EXE
      PID:364
    • C:\Users\Admin\AppData\Local\Temp\gFgtOqHgnlan.exe
      "C:\Users\Admin\AppData\Local\Temp\gFgtOqHgnlan.exe" 8 LAN
      2⤵
      • Executes dropped EXE
      PID:392
    • C:\Windows\SysWOW64\icacls.exe
      icacls "C:\*" /grant Everyone:F /T /C /Q
      2⤵
      • Modifies file permissions
      PID:30256
    • C:\Windows\SysWOW64\icacls.exe
      icacls "D:\*" /grant Everyone:F /T /C /Q
      2⤵
      • Modifies file permissions
      PID:34380
    • C:\Windows\SysWOW64\net.exe
      "C:\Windows\System32\net.exe" stop "audioendpointbuilder" /y
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:79320
      • C:\Windows\SysWOW64\net1.exe
        C:\Windows\system32\net1 stop "audioendpointbuilder" /y
        3⤵
          PID:100412
      • C:\Windows\SysWOW64\net.exe
        "C:\Windows\System32\net.exe" stop "audioendpointbuilder" /y
        2⤵
        • Suspicious use of WriteProcessMemory
        PID:79648
        • C:\Windows\SysWOW64\net1.exe
          C:\Windows\system32\net1 stop "audioendpointbuilder" /y
          3⤵
            PID:96180
        • C:\Windows\SysWOW64\net.exe
          "C:\Windows\System32\net.exe" stop "samss" /y
          2⤵
          • Suspicious use of WriteProcessMemory
          PID:96112
          • C:\Windows\SysWOW64\net1.exe
            C:\Windows\system32\net1 stop "samss" /y
            3⤵
              PID:100492
          • C:\Windows\SysWOW64\net.exe
            "C:\Windows\System32\net.exe" stop "samss" /y
            2⤵
            • Suspicious use of WriteProcessMemory
            PID:96120
            • C:\Windows\SysWOW64\net1.exe
              C:\Windows\system32\net1 stop "samss" /y
              3⤵
                PID:100392

          Network

          MITRE ATT&CK Enterprise v6

          Replay Monitor

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          Downloads

          • memory/1664-54-0x0000000076491000-0x0000000076493000-memory.dmp

            Filesize

            8KB