Analysis

  • max time kernel
    139s
  • max time network
    147s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20231130-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20231130-enlocale:en-usos:windows10-2004-x64system
  • submitted
    09/12/2023, 01:16

General

  • Target
    file.exe
  • Size 231KB
  • Sample231209-bmtecsdhbr
  • SHA256 4bfe3ac7d0659a4c07d3866d2c26b6efaca0eb296b27a0c7672e4eb0eb0987d6
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • stealc

C2
  • http://5.42.64.41

Attributes
  • url_path

    /40d570f44e84a454.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.

  • Loads dropped DLL 2 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.

  • Delays execution with timeout.exe 1 IoCs
  • Suspicious behavior: EnumeratesProcesses 2 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 6 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\file.exe
    "C:\Users\Admin\AppData\Local\Temp\file.exe"
    1⤵
    • Checks computer location settings
    • Loads dropped DLL
    • Checks processor information in registry
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    PID:4640
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\system32\cmd.exe" /c timeout /t 5 & del /f /q "C:\Users\Admin\AppData\Local\Temp\file.exe" & del "C:\ProgramData\*.dll"" & exit
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2220
      • C:\Windows\SysWOW64\timeout.exe
        timeout /t 5
        3⤵
        • Delays execution with timeout.exe
        PID:2408
    • C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 4640 -s 2304
      2⤵
      • Program crash
      PID:1108
  • C:\Windows\SysWOW64\WerFault.exe
    C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 4640 -ip 4640
    1⤵
      PID:4880
    • C:\Windows\system32\rundll32.exe
      "C:\Windows\system32\rundll32.exe" "C:\Windows\SYSTEM32\EDGEHTML.dll",#141 Microsoft.VCLibs.140.00_8wekyb3d8bbwe
      1⤵
        PID:4416
      • C:\Windows\System32\svchost.exe
        C:\Windows\System32\svchost.exe -k UnistackSvcGroup
        1⤵
        • Suspicious use of AdjustPrivilegeToken
        PID:4052

      Network

            MITRE ATT&CK Enterprise v15

            Replay Monitor

            Loading Replay Monitor...

            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

            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

            memory/4052-126-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-123-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-129-0x000001D173D40000-0x000001D173D41000-memory.dmp

            memory/4052-86-0x000001D16BA40000-0x000001D16BA50000-memory.dmp

            memory/4052-118-0x000001D173FF0000-0x000001D173FF1000-memory.dmp

            memory/4052-119-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-102-0x000001D16BB40000-0x000001D16BB50000-memory.dmp

            memory/4052-120-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-121-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-128-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-127-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-125-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-124-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4052-122-0x000001D175120000-0x000001D175121000-memory.dmp

            memory/4640-4-0x0000000061E00000-0x0000000061EF3000-memory.dmp

            memory/4640-1-0x00000000009C0000-0x0000000000AC0000-memory.dmp

            memory/4640-85-0x0000000000400000-0x000000000085C000-memory.dmp

            memory/4640-3-0x0000000000400000-0x000000000085C000-memory.dmp

            memory/4640-79-0x0000000000400000-0x000000000085C000-memory.dmp

            memory/4640-2-0x00000000025A0000-0x00000000025BC000-memory.dmp