stunnel.exe is an executable file associated with the software stunnel, a multiplatform SSL tunneling proxy. This software was developed by Michal Trojnara and is also associated with SWsoft. The file is typically located in the directory C:\Program Files (x86)\stunnel\bin.
Stunnel is a versatile tool used to provide a universal TLS/SSL tunneling service. It can be used to add SSL functionality to commonly used Inetd daemons like POP2, POP3, and IMAP servers without any changes in the program's code. It's also used for securing non-SSL aware software by having Stunnel provide the encryption, requiring no changes to the daemon's code.
Stunnel is needed when you want to secure non-SSL aware daemons and protocols to communicate over secure SSL channels. It can be used to secure non-SSL aware web servers with SSL encryption. It can also be used to tunnel an unencrypted network connection over an encrypted SSL connection.
If you didn't install this software intentionally, it could potentially be a security risk. Unwanted programs can sometimes use the same file names as legitimate software to hide their activities. If you find stunnel.exe on your computer and you didn't install it, or it's behaving suspiciously, you should remove it to ensure the security of your system.
Description: Stunnel.exe is not essential for Windows and will often cause problems. The file stunnel.exe is located in a subfolder of "C:\Program Files (x86)" (common is C:\Program Files (x86)\stunnel\bin\ or C:\Program Files (x86)\stunnel\).
Known file sizes on Windows 10/11/7 are 1,625,488 bytes (18% of all occurrences), 91,648 bytes and 12 more variants.
It is not a Windows core file. The application uses ports to connect to or from a LAN or the Internet. The program is not visible.
Stunnel.exe is able to monitor applications.
Therefore the technical security rating is 53% dangerous, however you should also read the user reviews.
Uninstalling this variant:
If any problems with Open Source Developer, Michal Trojnara or stunnel installed for AllUsers occur, you can also safely remove the program using the uninstall program of it (Control Panel ⇒ Uninstall a Program) or use the software publisher's support.
If stunnel.exe is located in a subfolder of the user's profile folder, the security rating is 84% dangerous. The file size is 180,224 bytes.
The application listens for or sends data on open ports to a LAN or the Internet. The stunnel.exe file is not a Windows core file. The program has no visible window.
Stunnel.exe is able to monitor applications.
Important: Some malware camouflages itself as stunnel.exe. Therefore, you should check the stunnel.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.
Score
User Comments
I have had nothing but possitive experiences with stunnel.exe. It has been integrated into several applicatons I wrote in order to add email functionality. TobY Sentinel
Program self installed from somewhere, I don't know where it came from. Thats the problem. No warnings, nothing. All of a sudden I noticed it was installing in the windows last used fike under the windows logo. Real suspicious. Robert
Summary: Average user rating of stunnel.exe:
based on 2 votes with 2 user comments.
One user thinks it's neither essential nor dangerous.
One user thinks stunnel.exe is dangerous and recommends removing it.
Best practices for resolving stunnel issues
A clean and tidy computer is the key requirement for avoiding problems with stunnel. This means running a scan for malware, cleaning your hard drive using 1cleanmgr and 2sfc /scannow, 3uninstalling programs that you no longer need, checking for Autostart programs (using 4msconfig) and enabling Windows' 5Automatic Update. Always remember to perform periodic backups, or at least to set restore points.
Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the 6resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or executing the 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.
To get your computer running as fast as it did on day one, you can 8reset your PC. Your personal files will remain intact, but any programs you installed will need to be reinstalled.
To help you analyze the stunnel.exe process on your computer, the following programs have proven to be helpful: ASecurity Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. A good Bantivirus software detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.
Score
User Comments
TobY Sentinel
Robert
Summary: Average user rating of stunnel.exe: based on 2 votes with 2 user comments. One user thinks it's neither essential nor dangerous. One user thinks stunnel.exe is dangerous and recommends removing it.