MSSprinkler – Enhancing M365 Security Through Advanced Password Testing

MSSprinkler is a password spraying utility for organizations to test their M365 accounts from an external perspective.

It employs a ‘low-and-slow’ approach to avoid locking out accounts, and provides verbose information related to accounts and tenant information.

Contents

• Description
• Current Feature
• Installation
• Help
• Disclaimer

Description

MSSprinkler is written in PowerShell and can be imported directly as a module. It has no other dependencies.

MSSprinkler relies on the verbose error messaging provided by Microsoft to identify additional information beyond standard password spray success or failed authentication attempts, which allows for the gathering of additional information related to the user account.

MSSprinkler also allows for a configurable threshold to prevent locking out accounts by mistake.

By default, this is set to 8 (n-2 under Microsoft’s default) however this can be adjusted based on the organizations lockout policy.

Additionally, successful sign-in to an account with MFA enabled will not produce an MFA push to the user, allowing for covert information gathering.

Current Features

• Automatically spray a list of M365 accounts with a password list.
• Low-and-slow approach to avoid locking out accounts.
• Smart detect accounts that do not exist or are locked out, skipping over these to reduce unnecessary traffic and speed up testing.
• Ability to override the default threshold to better match the organizations policy, if required.
• Verbose output, revealing additional information about accounts:
  • Detect if an account is locked out.
  • Detect if a user exists in the tenant or not.
  • Detect if MFA is in use for a given user without triggering the MFA push.
• Output and store results into a file

Install And Usage

# Import the module
Import-Module MSSprinkler.ps1

# Spray using a provided userlist and password list, default URL and threshold
Invoke-MSSprinkler -user userlist.txt -pass passwordlist.txt

# Spray using a provided userlist and password list, increase threshold to 12 attempts per min and output results to output.csv
Invoke-MSSprinkler -user userlist.txt -pass passwordlist.txt -threshold 12 -output .\output.csv