Analysis

  • max time kernel
    141s
  • max time network
    150s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20231222-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20231222-enlocale:en-usos:windows10-2004-x64system
  • submitted
    29/01/2024, 14:09

General

  • Target
    file.exe
  • Size 2.0MB
  • Sample240129-rf5rtabeb8
  • SHA256 5e19860c1c39cd2f59baec1bf7e9ecef6894612bd90fd4a7418e051fab415ca9
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • stealc

C2
  • http://185.172.128.79

Attributes
  • url_path

    /3886d2276f6914c4.php

rc4.plain

Signatures

  • Stealc

    Stealc is an infostealer written in C++.

  • Downloads MZ/PE file
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Executes dropped EXE 2 IoCs
  • Loads dropped DLL 5 IoCs
  • Reads data files stored by FTP clients 2 TTPs

    Tries to access configuration files associated with programs like FileZilla.

  • 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.

  • Enumerates physical storage devices 1 TTPs

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

  • Program crash 1 IoCs
  • Checks processor information in registry 2 TTPs 2 IoCs

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

  • Creates scheduled task(s) 1 TTPs 1 IoCs

    Schtasks is often used by malware for persistence or to perform post-infection execution.

  • Delays execution with timeout.exe 1 IoCs
  • Suspicious behavior: EnumeratesProcesses 2 IoCs
  • Suspicious use of SetWindowsHookEx 1 IoCs
  • Suspicious use of WriteProcessMemory 21 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\file.exe
    "C:\Users\Admin\AppData\Local\Temp\file.exe"
    1⤵
    • Loads dropped DLL
    • Suspicious use of WriteProcessMemory
    PID:4848
    • C:\Users\Admin\AppData\Local\Temp\BroomSetup.exe
      C:\Users\Admin\AppData\Local\Temp\BroomSetup.exe
      2⤵
      • Executes dropped EXE
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:4748
      • C:\Windows\SysWOW64\cmd.exe
        C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Roaming\Temp\Task.bat" "
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:3940
        • C:\Windows\SysWOW64\chcp.com
          chcp 1251
          4⤵
            PID:1996
          • C:\Windows\SysWOW64\schtasks.exe
            schtasks /create /tn "MalayamaraUpdate" /tr "'C:\Users\Admin\AppData\Local\Temp\Updater.exe'" /sc minute /mo 30 /F
            4⤵
            • Creates scheduled task(s)
            PID:2696
      • C:\Users\Admin\AppData\Local\Temp\nsz4661.tmp
        C:\Users\Admin\AppData\Local\Temp\nsz4661.tmp
        2⤵
        • Checks computer location settings
        • Executes dropped EXE
        • Loads dropped DLL
        • Checks processor information in registry
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of WriteProcessMemory
        PID:4228
        • C:\Windows\SysWOW64\cmd.exe
          "C:\Windows\system32\cmd.exe" /c timeout /t 5 & del /f /q "C:\Users\Admin\AppData\Local\Temp\nsz4661.tmp" & del "C:\ProgramData\*.dll"" & exit
          3⤵
          • Suspicious use of WriteProcessMemory
          PID:4444
          • C:\Windows\SysWOW64\timeout.exe
            timeout /t 5
            4⤵
            • Delays execution with timeout.exe
            PID:4028
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 4228 -s 2412
          3⤵
          • Program crash
          PID:2316
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 4228 -ip 4228
      1⤵
        PID:1656

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

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            Downloads

            Are.docx

            • Path C:\ProgramData\Are.docx
            • Size 11KB
            • SHA256 5abf8e3d1f78de7b09d7f6fb87f9e80e60caacf13ef3c1289665653dacd7c454
            • MD5 SHA1 SHA512 SSDEEP

            mozglue.dll

            • Path C:\ProgramData\mozglue.dll
            • Size 593KB
            • SHA256 ba06a6ee0b15f5be5c4e67782eec8b521e36c107a329093ec400fe0404eb196a
            • MD5 SHA1 SHA512 SSDEEP

            nss3.dll

            • Path C:\ProgramData\nss3.dll
            • Size 2.0MB
            • SHA256 ac5c92fe6c51cfa742e475215b83b3e11a4379820043263bf50d4068686c6fa5
            • MD5 SHA1 SHA512 SSDEEP

            BroomSetup.exe

            • Path C:\Users\Admin\AppData\Local\Temp\BroomSetup.exe
            • Size 4.7MB
            • SHA256 50a46b3120da828502ef0caba15defbad004a3adb88e6eacf1f9604572e2d503
            • MD5 SHA1 SHA512 SSDEEP

            INetC.dll

            • Path C:\Users\Admin\AppData\Local\Temp\nsy4305.tmp\INetC.dll
            • Size 25KB
            • SHA256 85e03805f90f72257dd41bfdaa186237218bbb0ec410ad3b6576a88ea11dccb9
            • MD5 SHA1 SHA512 SSDEEP

            nsz4661.tmp

            • Path C:\Users\Admin\AppData\Local\Temp\nsz4661.tmp
            • Size 335KB
            • SHA256 8952af1886c4433ffc0a3f31080ed526fccf87c99d248d6930af6c1c152dc442
            • MD5 SHA1 SHA512 SSDEEP

            Task.bat

            • Path C:\Users\Admin\AppData\Roaming\Temp\Task.bat
            • Size 128B
            • SHA256 6be22058abfb22b40a42fb003f86b89e204a83024c03eb82cd53e2a0a047c331
            • MD5 SHA1 SHA512

            memory/4228-24-0x0000000061E00000-0x0000000061EF3000-memory.dmp

            memory/4228-20-0x0000000000400000-0x000000000062E000-memory.dmp

            memory/4228-19-0x00000000006B0000-0x00000000006CC000-memory.dmp

            memory/4228-18-0x00000000007D0000-0x00000000008D0000-memory.dmp

            memory/4228-96-0x0000000000400000-0x000000000062E000-memory.dmp

            memory/4228-102-0x0000000000400000-0x000000000062E000-memory.dmp

            memory/4748-78-0x0000000000400000-0x00000000008E2000-memory.dmp

            memory/4748-7-0x0000000000AE0000-0x0000000000AE1000-memory.dmp

            memory/4748-109-0x0000000000AE0000-0x0000000000AE1000-memory.dmp