Analysis

  • max time kernel
    148s
  • max time network
    148s
  • platform
    windows10_x64
  • resource
    win10v20210410
  • submitted
    05/08/2021, 09:52

General

  • Target

    gunzipped.exe

  • Size

    1.0MB

  • MD5

    ea1c39e72ae5c05ccb6caf2d94db2235

  • SHA1

    3746a3696094d98a4f91103b045b894c38b04d37

  • SHA256

    40ef0ea8d499ef74760da82a71c8cf548149e01826b62767c75431cc4cdad67f

  • SHA512

    c47467c0af42160971b648564868b66d2870658eebfd68388f8b04208788f2ec753f9b3331a78041d68603eec2813c7ace7a624975b80146fda4eb63b8802eb3

Malware Config

Extracted

Family

remcos

Version

3.2.0 Pro

Botnet

RemoteHost

C2

ostriuyer.myddns.me:7116

Attributes
  • audio_folder

    MicRecords

  • audio_path

    %AppData%

  • audio_record_time

    5

  • connect_delay

    0

  • connect_interval

    1

  • copy_file

    remcos.exe

  • copy_folder

    Remcos

  • delete_file

    false

  • hide_file

    false

  • hide_keylog_file

    false

  • install_flag

    false

  • install_path

    %AppData%

  • keylog_crypt

    false

  • keylog_file

    logs.txt

  • keylog_flag

    false

  • keylog_folder

    remcos

  • keylog_path

    %AppData%

  • mouse_option

    false

  • mutex

    Remcos-MSOKMD

  • screenshot_crypt

    false

  • screenshot_flag

    true

  • screenshot_folder

    Screenshots

  • screenshot_path

    %AppData%

  • screenshot_time

    2

  • startup_value

    Remcos

  • take_screenshot_option

    false

  • take_screenshot_time

    5

  • take_screenshot_title

    notepad;solitaire;

Extracted

Family

oski

C2

marbellacabs.com/hao/

Signatures

  • Oski

    Oski is an infostealer targeting browser data, crypto wallets.

  • Remcos

    Remcos is a closed-source remote control and surveillance software.

  • Downloads MZ/PE file
  • Executes dropped EXE 2 IoCs
  • Loads dropped DLL 3 IoCs
  • Reads user/profile data of web browsers 2 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

  • Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
  • Checks installed software on the system 1 TTPs

    Looks up Uninstall key entries in the registry to enumerate software on the system.

  • Suspicious use of SetThreadContext 4 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Checks processor information in registry 2 TTPs 1 IoCs

    Processor information is often read in order to detect sandboxing environments.

  • Kills process with taskkill 1 IoCs
  • Suspicious behavior: EnumeratesProcesses 4 IoCs
  • Suspicious use of AdjustPrivilegeToken 4 IoCs
  • Suspicious use of SetWindowsHookEx 1 IoCs
  • Suspicious use of WriteProcessMemory 49 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\gunzipped.exe
    "C:\Users\Admin\AppData\Local\Temp\gunzipped.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:3484
    • C:\Users\Admin\AppData\Local\Temp\gunzipped.exe
      "C:\Users\Admin\AppData\Local\Temp\gunzipped.exe"
      2⤵
      • Suspicious use of SetThreadContext
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:2500
      • C:\Users\Admin\AppData\Roaming\srsc.exe
        "C:\Users\Admin\AppData\Roaming\srsc.exe"
        3⤵
        • Executes dropped EXE
        • Suspicious use of SetThreadContext
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        • Suspicious use of WriteProcessMemory
        PID:2424
        • C:\Users\Admin\AppData\Roaming\srsc.exe
          "C:\Users\Admin\AppData\Roaming\srsc.exe"
          4⤵
          • Executes dropped EXE
          • Loads dropped DLL
          • Checks processor information in registry
          • Suspicious use of WriteProcessMemory
          PID:2144
          • C:\Windows\SysWOW64\cmd.exe
            "C:\Windows\System32\cmd.exe" /c taskkill /pid 2144 & erase C:\Users\Admin\AppData\Roaming\srsc.exe & RD /S /Q C:\\ProgramData\\280077228644132\\* & exit
            5⤵
            • Suspicious use of WriteProcessMemory
            PID:2008
            • C:\Windows\SysWOW64\taskkill.exe
              taskkill /pid 2144
              6⤵
              • Kills process with taskkill
              • Suspicious use of AdjustPrivilegeToken
              PID:3836
      • C:\Users\Admin\AppData\Local\Temp\gunzipped.exe
        C:\Users\Admin\AppData\Local\Temp\gunzipped.exe /stext "C:\Users\Admin\AppData\Local\Temp\bqnrcgjouvtcjovryhasqhpev"
        3⤵
          PID:2308
        • C:\Users\Admin\AppData\Local\Temp\gunzipped.exe
          C:\Users\Admin\AppData\Local\Temp\gunzipped.exe /stext "C:\Users\Admin\AppData\Local\Temp\mkskdzuiidlhlusvpsmttmkvwiwjw"
          3⤵
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          PID:348
        • C:\Users\Admin\AppData\Local\Temp\gunzipped.exe
          C:\Users\Admin\AppData\Local\Temp\gunzipped.exe /stext "C:\Users\Admin\AppData\Local\Temp\omyverfjwldmvigzychvezxeepgspwvv"
          3⤵
            PID:1208

      Network

            MITRE ATT&CK Enterprise v6

            Replay Monitor

            Loading Replay Monitor...

            Downloads

            • memory/348-144-0x0000000000400000-0x0000000000424000-memory.dmp

              Filesize

              144KB

            • memory/348-138-0x0000000000400000-0x0000000000424000-memory.dmp

              Filesize

              144KB

            • memory/1208-140-0x0000000000400000-0x0000000000457000-memory.dmp

              Filesize

              348KB

            • memory/1208-145-0x0000000000400000-0x0000000000457000-memory.dmp

              Filesize

              348KB

            • memory/2144-148-0x0000000000400000-0x0000000000438000-memory.dmp

              Filesize

              224KB

            • memory/2144-151-0x0000000000400000-0x0000000000438000-memory.dmp

              Filesize

              224KB

            • memory/2424-146-0x0000000009B10000-0x0000000009BA3000-memory.dmp

              Filesize

              588KB

            • memory/2424-131-0x0000000000A10000-0x0000000000A11000-memory.dmp

              Filesize

              4KB

            • memory/2424-147-0x000000000BF70000-0x000000000BFA4000-memory.dmp

              Filesize

              208KB

            • memory/2424-141-0x0000000005410000-0x000000000590E000-memory.dmp

              Filesize

              5.0MB

            • memory/2500-127-0x0000000000400000-0x0000000000479000-memory.dmp

              Filesize

              484KB

            • memory/2500-125-0x0000000000400000-0x0000000000479000-memory.dmp

              Filesize

              484KB

            • memory/3484-121-0x0000000004F90000-0x0000000004F91000-memory.dmp

              Filesize

              4KB

            • memory/3484-114-0x00000000006B0000-0x00000000006B1000-memory.dmp

              Filesize

              4KB

            • memory/3484-123-0x0000000009AE0000-0x0000000009BB1000-memory.dmp

              Filesize

              836KB

            • memory/3484-122-0x0000000005420000-0x0000000005433000-memory.dmp

              Filesize

              76KB

            • memory/3484-124-0x000000000BFC0000-0x000000000C035000-memory.dmp

              Filesize

              468KB

            • memory/3484-120-0x0000000005280000-0x0000000005281000-memory.dmp

              Filesize

              4KB

            • memory/3484-119-0x0000000005080000-0x0000000005081000-memory.dmp

              Filesize

              4KB

            • memory/3484-118-0x0000000005120000-0x0000000005121000-memory.dmp

              Filesize

              4KB

            • memory/3484-117-0x0000000005580000-0x0000000005581000-memory.dmp

              Filesize

              4KB

            • memory/3484-116-0x0000000004FE0000-0x0000000004FE1000-memory.dmp

              Filesize

              4KB