Active Directory User Scanner

Active Directory User Scanner is a C++ application that scans all computers in a Windows domain and collects logged-on users. The output is saved in a CSV file compatible with Excel. The tool supports multithreading for faster scanning in large environments.

Features

• Scan all computers in an Active Directory domain
• List logged-on users for each computer
• Save results as UTF-8 BOM CSV (Excel compatible)
• Multithreading support for faster processing
• Registry-based SID-to-username resolution
• Error handling and reporting

Requirements

• Windows operating system
• Visual Studio 2022
• Windows SDK
• wldap32.lib (for LDAP operations)

File Structure

File	Description
main.cpp	Entry point of the program. Handles command-line arguments and starts the AD scanning process.
ADHelper.h/.cpp	Helper class for simplifying Active Directory operations, including fetching computers and users.
LDAPQuery.h/.cpp	Low-level LDAP query class. Manages LDAP connection, bind, and search operations.
ReportGenerator.h/.cpp	Responsible for generating the CSV report, writing data, and tracking statistics.

Compilation

• Download the project to your computer.
• Extract the Project to a Folder.
• Download Visual Studio to your computer
• Open the solution file (.sln).
• Select Build Solution from the Build menu.

Usage

Run the program from the command line:

program.exe -d <domain> -dc <domain_controller> -o <output_file> [options]

Required Parameters

• -d, --domain → Domain name (e.g., example.com)
• -dc, --dc → Domain Controller address (e.g., dc.example.com)
• -o, --output → Output CSV file (e.g., report.csv)

Optional Parameters

• -t, --threads → Number of threads (default: 100, maximum: 500)
• -h, --help → Show help message

Example

program.exe -d example.com -dc dc.example.com -o report.csv -t 50

Classes and Functions

ReportGenerator

Purpose: Writes scanning results to a CSV file and keeps statistics.

Key Functions:

• Initialize() → Creates the CSV file and writes the header row
• AddEntry(const ComputerInfo&, const std::vector<UserInfo>&) → Adds computer and user information (thread-safe)
• Close() → Closes the CSV file and prints a summary
• GetTotalComputers(), GetComputersWithUsers(), GetTotalUsers() → Retrieve statistics

Helper Functions:

• WStringToUTF8 → Converts std::wstring to UTF-8 std::string
• EscapeCSV → Escapes commas, quotes, and newlines for CSV compatibility

LDAPQuery

Purpose: Handles low-level LDAP operations using Windows LDAP API.

Key Functions:

• Initialize() → Initialize LDAP connection
• Bind() → Perform LDAP bind using negotiated authentication
• Search(baseDN, filter, attributes) → Execute an LDAP search
• GetAttributeValues(attributeName) → Retrieve values for a specific attribute
• GetLastError() → Retrieve the last LDAP error

ADHelper

Purpose: Simplifies LDAP queries and Active Directory operations.

Key Functions:

• GetAllComputers() → Retrieve all computers in the domain
• GetComputerOS(computerName) → Retrieve the operating system of a computer
• GetLoggedOnUsers(fqdn) → Retrieve users logged in on a specific computer
• DomainToDN(domain) → Convert a domain name to LDAP DN format
• ExtractComputerName(fqdn, domain) → Extract the computer name from its FQDN

main.cpp Workflow

1. Parse command-line arguments (ParseArguments)
2. Initialize ADHelper and ReportGenerator
3. Retrieve all computers from Active Directory (GetAllComputers)
4. Divide computers among threads for multithreaded scanning (ProcessComputerBatch)
5. Add logged-on users to CSV file
6. Print a summary when scanning is complete

Example CSV Output

Computer,OS,SID,Logon User
PC1,Windows 10,, 
PC2,Windows Server 2019,S-1-5-21-1234567890-1234567890-1234567890-1001,"DOMAIN\User1"
PC2,Windows Server 2019,S-1-5-21-1234567890-1234567890-1234567890-1002,"DOMAIN\User2"

• Computers without users only display computer info
• Each user gets a separate row

Multithreading

• Uses std::async and std::future
• Computer list is divided across threads
• Each thread processes a batch of computers
• ReportGenerator::AddEntry ensures thread-safe writes to CSV

Error Handling

• LDAP and registry errors are logged
• Inaccessible computers are skipped silently
• Error messages are written to std::wcerr

License

This project is licensed under the MIT License. For more information, see the LICENSE file.