Did you just find a file that has been digitally signed by stronghold.com? If that's the case, please read on.
You will probably notice stronghold.com when clicking to run the file. The publisher name is displayed as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view additional details from the stronghold.com certificate with the following procedure:
Here is a screenshot of a file signed by stronghold.com:

As you can see in the screencap above, Windows states that "This digital signature is OK". This implies that the file has been published by stronghold.com and that no one has tampered with the file.
If you click the View Certificate button shown in the screenshot above, you can see all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, etc. You can also see the address for stronghold.com, such as the street name, city and country.
VeriSign Class 3 Code Signing 2010 CA has issued the stronghold.com certificates. You can also examine the details of the issuer by clicking the View Certificate button shown in the screenshot above.
These are the stronghold.com files I have collected, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 0/54 | SMessenger.exe |
The detection percentage is based on that I've collected 54 scan reports for the stronghold.com files. 0 of these scan reports came up with some sort of detection. You can view the full details of the scan reports by examining the files listed above.
The analysis is based on certificates with the following serial numbers: