Did you just stumble upon a download or a file on your computer that has been digitally signed by U3 LLC? If so, please read on.
You will typically notice U3 LLC when clicking to run the file. The publisher name is then displayed as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view additional details from the U3 LLC certificate with the following procedure:
Here is a screengrab of a file digitally signed by U3 LLC:

As you can see in the screenshot above, Windows states that "This digital signature is OK". This implies that the file has been published by U3 LLC and that the file has not been tampered with.
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, etc. You can also see the address for U3 LLC, such as the street name, city and country.
VeriSign Class 3 Code Signing 2004 CA has issued the U3 LLC certificates. You can also see the details of the issuer by clicking the View Certificate button shown in the screenshot above.
The following are the U3 LLC files I have collected, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 0/47 | LaunchU3.exe |
| 0/45 | LaunchU3.exe |
| 0/56 | LaunchU3.exe |
The detection percentage is based on the fact that I have collected 148 scan results for the U3 LLC files. 0 of these scan results came up with some sort of detection. You can view the full details of the scan results by examining the files listed above.
The analysis is based on certificates with the following serial numbers: