External Pentest

Type of External Pentest

The Type of External Penetration Test to be conducted should be clearly defined

• Blackbox External Pentest :

This test is expected to be conducted without any knowledge of the Internet facing IP addresses,the website, or web application.

• White Box External Pentest :

This test is expected to be conducted with the knowledge of the organization's Internet facing IP addresses,the website,web application, or some other range of IP public addresses that will be shared with you by the organization.

The type of the external penetration test must be clearly stated in the rules of engagement.

Rules of engagement

• The doc should be signed and as a pentester you should have a copy

Verify scope

Step 1

• Scan the IP addess with this to verify it actually belongs to the company

Step 2

Subdomain Finders

• This will help identify a lot of IPs and web application for scoping and testing purposes

  • subdomainfinder

  • phonebook

Using Google Dork

• Type in google

  • site:nameofcompany.com -www

  • site : nameofcompany.com

  • site: *.nameofcompany.com

Subdomain tools

• AMASS

• SubBrute

• Knock

• DNSRecon

• Sublist3r

• AltDNS

• Axiom

• Haktrails

• Check out this article on securitytrails to see how to use the above tools

Vuln Scan

Todo first thing in the morning

• OpenVAS - Open Source

• Nessus

OSINT

Hunting breach credentials

• breach-parse

• Dehashed

• Have I been Pwned

Identifying Emails & Employees

• Get info on the naming convention for email (firstname.lastname or else)

• Phonebook, find email address

• Look for the company on Linkedin, use tools to scrape Linkedin and put them together using the deducted naming convention

  • We can use Namely to put them together and specify a naming convention that will be applied to the whole list

Enumerating valid accounts

• Check login form or password reset forms for user enum

Other useful info

• Job postings (info about app used at the company)

• Google dork to find password policy (site:target)

How to check a host OS

• Time to Live (TTL) A typical response from a Windows host will either be 32 or 128. A response of or around 128 is the most common response you will see. This value may not always be exact, especially if you are not in the same layer three network as the target.

• Default Device TTL values

• sudo nmap -v -O TARGET-IP nmap OS Detection Scan

• sudo nmap -v 192.168.86.39 --script banner.nse Banner Grab to Enumerate Ports

Attack login portals

• Password strategy: currentSeasonOrMonth+currentYear+aSpecialChar, location, address, company name, ...

O365

• Password Spraying

  • TREVORspray

  • We use the email list from the reconnaissance phase

  • Good to start with a delay of 15 --delay 15

  • --no-current-ip will proxy through each machine, more stealthy

  • Careful with account lockout = good to know account lockout policy prior to pentest

  • Using AWS we can make multiple ubuntu machine for free

  • Trevorspray is going to ssh first we have to accept fingerprinting everytime and then it is going to password spray

  • Trevorspsray will remember which pass previously used

OWA (Outlook Web Access)

• Password Spraying

  • Metasploit: Scanner owa_login

  • set a password

  • set an RHOST (IP adr of target)

  • set user_file

  • checkout owa version to be sure it is the same

  • Even if pass does not work we will get a list of valid users

Other portals

• Burp Suite Intruder (works better with pro version)

  • Intercept a request and set the vars

  • Check out the error message and add it in intruder options (Grep Match)

  • Launch intruder

Bypassing MFA

• MFASweep

Escalating Access

• If we get an email account, office for instance we can look for info or creds in the mailbox

• portal.azure.com if you login with a user you found you can find other accounts

• Then password spray with previous password found

• Be creative

Common pentest findings

Insufficient Authentication Controls

• Bypass MFA

• No MFA

Weak Password Policy

• Recommand deny list

• Recommand NIST or OWASP Guidelines

Insufficient Patching

• Some unpatch software have high severity CVE

Default Credentials

• List of default creds - SecLists

• Default Passwords - Cirt

• Default creds cheat sheet - ihebski

Insufficient Encryption

• In case of http

• Weak ciphers

• TestSSL

• SSLLabs Note: Make sure to check "Do not show results on boad" for the confidentiality of your customer

Information Disclosure

• Verbose error message

• Verbose stack trace

• mDNS

• Server version and languages in response header

Username Enumeration

• Most of the time visible through login portals with msg like "Invalid username"

• Possible also through reset password forms

Default Web Pages

• Apache Pages

• IIS Page

Open Mail Relay

• How to test for Open mail relays - BlackHills Infosec

IKE Aggressive Mode

• Could capture a preshared key of a vpn to access the network (most of the time hard to exploit)

• ike-scan

Unexpected Perimeter Services

• RDP

• Telnet

• etc.

Insufficient Traffic Blocking

• Shotsherpa

• Geo-blocking not in place

• Limits attack surface

• Depends on the customer location of the client

Undetected Malicious Activity

• Bruteforce login attacks

• Nmap

• Nessus

• Web enum bruteforce

• etc.

Historical Account Compromises

• Published breaches

• haveibeenpawned

Resources

External Pentest Playbook - TCM SecurityTCM Security - Cyber Security

TCM Academy - External Pentest Playbook

GitHub - blacklanternsecurity/TREVORspray: TREVORspray is a modular password sprayer with threading, clever proxying, loot modules, and more!GitHub

TREVORspray

GitHub - dafthack/MFASweep: A tool for checking if MFA is enabled on multiple Microsoft ServicesGitHub

MFASweep

GitHub - dafthack/MailSniper: MailSniper is a penetration testing tool for searching through email in a Microsoft Exchange environment for specific terms (passwords, insider intel, network architecture information, etc.). It can be used as a non-administrative user to search their own email, or by an administrator to search the mailboxes of every user in a domain.GitHub

Mailsniper

SecLists/Passwords/Default-Credentials at master · danielmiessler/SecListsGitHub

List of default creds - SecLists

Default Password Database - cirt.netcirt.net

Default Passwords - Cirt

DefaultCreds-cheat-sheet/DefaultCreds-Cheat-Sheet.csv at main · ihebski/DefaultCreds-cheat-sheetGitHub

Default creds cheat sheet - ihebski

How to Test for Open Mail Relays - Black Hills Information Security, Inc.Black Hills Information Security, Inc.

How to test for Open mail relays - BlackHills Infosec

GitHub - royhills/ike-scan: The IKE ScannerGitHub

ike-scan

Have I Been Pwned: Check if your email address has been exposed in a data breachHave I Been Pwned

haveibeenpawned