Did you just stumble upon a file that is digitally signed by Systemline LLC? If that's the case, please read on.
You'll probably notice Systemline LLC when clicking to run the file. The publisher name is displayed as the "Verified publisher" in the UAC dialog as the screencap shows:

You can view the digital signature details for Systemline LLC with the following steps:
Here is a screengrab of a file signed by Systemline LLC:

As you can see in the screenshot above, the Windows OS states that "This digital signature is OK". This implies that the file has been published by Systemline LLC and that no one has tampered with the file.
If you click the View Certificate button shown in the screenshot above, you can view 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 view the address for Systemline LLC, such as the street name, city and country.
Thawte Code Signing CA has issued the Systemline LLC certificates. You can also examine the details of the issuer by clicking the View Certificate button shown in the screenshot above.
The following are the Systemline LLC files I've collected, thanks to the FreeFixer users.Unfortunately I don't have any scan result from VirusTotal available for the Systemline LLC files at the moment. The scan results will appear here as soon as a FreeFixer user uploads a file digitally signed by Systemline LLC.
| Detection Ratio | File Name |
|---|---|
| Not available | rpcsetup.exe |
The analysis has been done on certificates with the following serial numbers: