Did you just run into a file that has a digital signature from Piotr Kowaluk? If so, please read on.
You'll probably notice Piotr Kowaluk when running the file. The publisher name shows up as the "Verified publisher" in the UAC dialog as the screengrab shows:

You can view the digital signature details for Piotr Kowaluk with the following steps:
Here is a screencap of a file digitally signed by Piotr Kowaluk:

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 Piotr Kowaluk and that the file has not been tampered with.
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, and so on. You can also examine the address for Piotr Kowaluk, such as the street name, city and country.
Certum Code Signing CA SHA2 has issued the Piotr Kowaluk certificates. You can also view the details of the issuer by clicking the View Certificate button shown in the screenshot above.
The following are the Piotr Kowaluk files I've collected, thanks to the FreeFixer users.Unfortunately I don't have any scan result from VirusTotal available for the Piotr Kowaluk files at the moment. The scan results will appear here as soon as a FreeFixer user uploads a file digitally signed by Piotr Kowaluk.
| Detection Ratio | File Name |
|---|---|
| Not available | br32v.exe |
The analysis is based on certificates with the following serial numbers: