Did you just run into a file that is digitally signed by Linden Lab? If that's the case, please read on.
You will typically notice Linden Lab when double-clicking to run the file. The publisher name shows up as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can also view the Linden Lab certificate with the following steps:
Here's a screenshot of a file that has been digitally signed by Linden Lab:

As you can see in the screengrab above, the Windows OS states that "This digital signature is OK". This implies that the file has been published by Linden Lab and that no one has tampered with the file.
If you click the View Certificate button shown in the screenshot above, you can examine all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, and so on. You can also examine the address for Linden Lab, such as the street name, city and country.
COMODO RSA Code Signing CA and COMODO Code Signing CA 2 has issued the Linden Lab certificates. You can also examine the details of the issuer by clicking the View Certificate button shown in the screenshot above.
These are the Linden Lab files I have collected, thanks to the FreeFixer users.Unfortunately I don't have any scan result from VirusTotal available for the Linden Lab files at the moment. The scan results will appear here as soon as a FreeFixer user uploads a file digitally signed by Linden Lab.
| Detection Ratio | File Name |
|---|---|
| Not available | Second_Life_5_0_7_328060_i686_Setup.exe |
| Not available | Second_Life_3-2-1-244864_Setup.exe |
| Not available | Second_Life_3_7_5_288464_i686_Setup.exe |
| Not available | Second_Life_4_0_7_318301_i686_Setup.exe |
The analysis is based on certificates with the following serial numbers: