PsExec is a powerful command-line utility developed by Mark Russinovich as part of Microsoft’s Sysinternals Suite. It’s widely used by system administrators to remotely execute processes on Windows machines—without needing to install software on the remote system.

⚙️ What PsExec Does

• Launches interactive command prompts on remote systems
• Executes scripts or programs remotely
• Runs processes under different user accounts
• Enables remote troubleshooting and automation

🧠 How PsExec Works

PsExec uses Windows administrative shares (like \\ADMIN$) and the Service Control Manager (SCM) to:

1. Copy a small executable (PSEXESVC.exe) to the remote machine
2. Launch the desired command or script
3. Return the output to the local console

Example command:

psexec \\RemotePC -u AdminUser -p Password cmd

This opens a remote shell on RemotePC using specified credentials.

🔐 Security Considerations

• Requires admin privileges on the remote machine
• Transmits credentials in plaintext unless used over a secure channel
• Can be abused by attackers for lateral movement in post-exploitation scenarios

🛡️ Defensive Tips

• Restrict access to administrative shares
• Monitor for PsExec usage in logs (e.g., creation of PSEXESVC.exe)
• Use endpoint detection tools to flag unauthorized remote execution
• Consider alternatives like PowerShell Remoting with proper authentication

For more details and real-world examples, check out Microsoft’s official PsExec documentation or this extensive guide from Adam the Automator.