Did you just stumble upon a file that has a digital signature from OSA Technologies? If that's the case, please read on.
You'll probably see OSA Technologies 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 also view the OSA Technologies certificate with the following procedure:
Here's a screencap of a file signed by OSA Technologies:

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 OSA Technologies 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 view the address for OSA Technologies, such as the street name, city and country.
VeriSign Class 3 Code Signing 2004 CA has issued the OSA Technologies certificates. You can also see the details of the issuer by clicking the View Certificate button shown in the screengrab above.
The following are the OSA Technologies files I've collected, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 0/47 | osaio.sys |
| 0/47 | osaio.sys |
| 0/41 | osanbm.sys |
| 0/46 | osaio.sys |
| 0/57 | osaio.sys |
| 0/46 | netlimiter.sys |
The detection percentage is based on that I've gathered 284 scan results for the OSA Technologies files. 0 of these scan reports 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: