Did you just find a file that has a digital signature from ReactOS Foundation? If that's the case, please read on.
You will probably see ReactOS Foundation when running the file. The publisher name is then displayed as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view the digital signature details for ReactOS Foundation with the following steps:
Here's a screenshot of a file digitally signed by ReactOS Foundation:

As you can see in the screenshot above, the Windows OS reports that "This digital signature is OK". This means that the file has been published by ReactOS Foundation and that no one has tampered with the file.
If you click the View Certificate button shown in the screengrab 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 ReactOS Foundation, such as the street name, city and country.
VeriSign Class 3 Code Signing 2010 CA and VeriSign Class 3 Code Signing 2004 CA has issued the ReactOS Foundation 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 ReactOS Foundation files I have gathered, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 2/48 | kprocesshacker.sys |
| 2/67 | dcrypt.sys |
| 0/41 | dcrypt.sys |
| 0/44 | dc_fsf.sys |
| 0/56 | dcrypt.sys |
| 0/41 | dcrypt.sys |
| 0/47 | _iu14D2N.tmp |
Here is the detection names for the ReactOS Foundation files. I have grouped the detection names by each scanner engine. Thanks to VirusTotal for the scan results.
| Scanner | Detection Names |
|---|---|
| Antiy-AVL | RiskTool/Win64.PHack |
| Jiangmin | Trojan.BadRabbit.f |
| Kaspersky | not-a-virus:RiskTool.Win64.PHack.b |
| Tencent | Win32.Trojan.Badrabbit.Manf |
The detection percentage is based on the fact that I have collected 344 scan reports for the ReactOS Foundation files. 4 of these scan reports came up with some sort of detection. You can review the full details of the scan results by examining the files listed above.
The analysis has been done on certificates with the following serial numbers: