Did you just find a download or a file on your computer that is digitally signed by Guiffy Software, Inc.? If that's the case, please read on.
You will probably notice Guiffy Software, Inc. when double-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 Guiffy Software, Inc. certificate with the following procedure:
Here is a screenshot of a file signed by Guiffy Software, Inc.:

As you can see in the screenshot above, Windows reports that "This digital signature is OK". This means that the file has been published by Guiffy Software, Inc. and that the file has not been tampered with.
If you click the View Certificate button shown in the screencap 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 view the address for Guiffy Software, Inc., such as the street name, city and country.
COMODO RSA Code Signing CA has issued the Guiffy Software, Inc. certificates. You can also see the details of the issuer by clicking the View Certificate button shown in the screengrab above.
These are the Guiffy Software, Inc. files I've collected, thanks to the FreeFixer users.Unfortunately I don't have any scan result from VirusTotal available for the Guiffy Software, Inc. files at the moment. The scan results will appear here as soon as a FreeFixer user uploads a file digitally signed by Guiffy Software, Inc..
| Detection Ratio | File Name |
|---|---|
| Not available | guf119ins.exe |
The analysis is done on certificates with the following serial numbers: