CredSpy

Enumerate Microsoft Entra ID authentication methods for email addresses using the public GetCredentialType API. This is the same endpoint the Microsoft login page uses when you enter a username. In contrast to most tools using the GetCredentialType method, CredSpy also shows the authentication methods supported for existing accounts.

Useful for security assessments: user enumeration, preferred auth method discovery, and identifying accounts with password, Remote NGC (e.g. Passwordless Push Notification), FIDO2/passkeys, or certificate auth.

Table of contents

• Installation
• Usage
  • Options
• Output
  • CSV columns
• How it works
• Disclaimer

Installation

Requires Python 3.10+.

pipx (recommended):

# Install pipx (skip this if you already have it)
apt install pipx
pipx ensurepath

# From PyPI (recommended)
pipx install credspy

# Or from GitHub
pipx install git+https://github.com/RedByte1337/CredSpy.git

# From a local clone
git clone https://github.com/RedByte1337/CredSpy.git
cd CredSpy
pipx install .

pip:

pip install .
# or run without installing
pip install -r requirements.txt
python credspy.py ...

After installation, run credspy from anywhere:

credspy -h

Usage

# Single email
credspy user@example.com

# File of emails (one per line, # for comments)
credspy emails.txt

# Through a proxy (SSL verification disabled for MITM tools)
credspy emails.txt --proxy http://127.0.0.1:8080

# Export results to CSV
credspy emails.txt --csv results.csv

# Save filtered email lists (combinable)
credspy emails.txt \
  --save-existing existing.txt \
  --save-ngc ngc.txt \
  --save-password-preferred password-preferred.txt

Options

If any output file already exists, you are prompted to confirm overwrite (Y/n).

Output

Results stream to the terminal as each email is checked:

redbyte@e-corp.com       | Preferred: Fido (7)       | Supported: Password, RemoteNGC (PushNotification), Fido (Count: 3)
nonexistent@e-corp.com   | IfExistsResult: NotExist (1)
admin@e-corp.com         | Preferred: Password (1)   | Supported: Password, RemoteNGC (PushNotification)
alice@e-corp.com         | Preferred: RemoteNGC (2)  | Supported: Password, RemoteNGC (PushNotification)
bob@e-corp.com           | Preferred: Fido (7)       | Supported: Password, Fido (Count: 5), Certificate

If the email account exists, the first column after the email address will show the preferred authentication method for the user. The last column will list the other supported authentication methods such as Password, RemoteNGC, Fido (=PassKeys), and Certificate authentication.

All of this information is very useful to take into consideration when preparing for phishing attacks.

For Fido authentication, the number of entries in the AllowList of the FidoParams returned by Microsoft is shown. This can be used as an indicator to know how many Fido auth methods the user has enrolled. However, it seems like this also includes deleted Fido keys which are not linked to the account anymore.

A summary is printed at the end:

--- Summary ---
Exists: 6/7
Throttled: 0/7
Preferred: Fido 3/6, Password 2/6, ...
Supported: Password 6/6, RemoteNGC 1/6, Fido 3/6, Certificate 2/6
DomainType: Managed 6/6

--- Output files ---
CSV (results.csv): 7 entries

CSV columns

Email, Exists, PreferredType, HasPassword, RemoteNGC, HasFido, HasCertAuth, DomainType

• Exists — enum name (Exists, NotExist, …)
• RemoteNGC — PushNotification / ListSessions when known, otherwise True/False

How it works

1. Fetch a session context (sCtx) from the Microsoft OAuth authorize page
2. POST each username to login.microsoftonline.com/common/GetCredentialType
3. Parse credential flags and print / export results

No authentication required. This uses the same unauthenticated flow as the login UI.

Disclaimer

This tool is intended for authorized security testing and research only. Only use it against tenants and accounts you own or have explicit written permission to test. The authors are not responsible for misuse.