putty.exe

What is putty.exe?

putty.exe is the Windows executable for PuTTY, the classic SSH, Telnet, and Rlogin client. It provides a terminal emulation window and supports remote connections, tunneling, and simple file transfers via related PuTTY utilities.

PuTTY operates as a single-user SSH/Telnet client with optional companion tools (pscp, psftp, plink, pageant). It uses a small, event-driven UI and negotiates SSH authentication, ciphers, and session tunnels.

Types of PuTTY Processes

• PuTTY Client Process: Main session window and SSH/Telnet connection
• Plink Process: Command-line SSH/Telnet sessions
• PSCP/PSFTP Process: File transfer sessions built on SSH
• Pageant Process: SSH authentication agent for keys

Is putty.exe Safe?

Yes, putty.exe is Safe when obtained from official sources (https://www.chiark.greenend.org.uk/~sgtatham/putty/) or trusted package managers. Ensure the file is the legitimate PuTTY binary.

Is putty.exe a Virus or Malware?

The real putty.exe is not a virus. Malware may mimic names, so verify the signer and file path.

How to Tell if putty.exe is Legitimate or Malware

1. File Location: Must be in C:\Program Files\PuTTY\putty.exe or C:\PuTTY\putty.exe. Any other path is suspicious.
2. Digital Signature: Right-click putty.exe in Explorer -> Properties -> Digital Signatures. Should show signer "Simon Tatham".
3. Resource Usage: Normal PuTTY activity is minimal; CPU generally 0-5% during active input, memory ~5-20 MB per session.
4. Behavior: PuTTY launches on demand for SSH/Telnet, not as a background service. Constant background activity outside sessions is suspicious.

Why Is putty.exe Running on My PC?

putty.exe runs when you start an SSH/Telnet session with PuTTY or when related tools like Pageant are loaded to provide authentication keys.

Reasons it's running:

• Active SSH/Telnet Session: You have an open PuTTY session; each connection creates a process for the session window.
• Key Authentication: Pageant or PuTTY's key agent may be loaded to supply SSH keys to servers.
• Startup or Quick Launch: PuTTY may be configured to run at user login or from a startup shortcut.
• Automated Tasks: Background scripts or scheduled tasks trigger Plink/PSCP for backups or remote commands.
• Session Manager: PuTTY session manager utilities or wrappers may spawn putty.exe to manage connections.

Can I Disable or Remove putty.exe?

Yes, you can disable putty.exe. If you don't use PuTTY, uninstall it; otherwise close sessions and remove startup shortcuts.

How to Stop putty.exe

• End Active Sessions: In PuTTY, close the session window or choose Exit. If using Pageant, unload keys.
• Close PuTTY: Exit all PuTTY windows; ensure no child processes remain.
• Prevent Startup: Remove PuTTY shortcuts from Startup folder or disable any startup entry in Task Manager.
• Stop Automated Tasks: If you have scheduled tasks (Plink/PSCP), disable them in Task Scheduler.
• Check for Services: PuTTY is not a service; ensure no service is named PuTTY; remove if present.

How to Uninstall PuTTY

• ✔ Windows Settings -> Apps -> PuTTY -> Uninstall
• ✔ Control Panel -> Programs -> Programs and Features -> PuTTY -> Uninstall
• ✔ Delete PuTTY directory (C:\Program Files\PuTTY) if empty

Common Problems: SSH/Telnet Sessions

If putty.exe or PuTTY sessions have issues, review common causes and fixes.

Common Causes & Solutions

• Authentication failures: Verify correct username, password, or key pair; ensure key is loaded in Pageant.
• Connection refused: Check server availability, correct hostname/IP, and port (22 for SSH).
• Host key verification failed: Accept the host key, or update known_hosts; check for MITM.
• Key agent not loaded: Ensure Pageant is running and has the private key loaded.
• Timeouts: Investigate network latency; use -ssh option; test with ping/traceroute.
• Wrong tunnel configuration: Review forwarded ports; ensure local/remote mappings are correct.

Related Processes