Did you just run into a download or a file on your computer that is digitally signed by Ez-download? Some of the security products refers to the detected files as a variant of Win32/Toolbar.MyWebSearch.S and Win32.SuspectCrc. The detection rate for the Ez-download files collected here is 11%. Please read on for more details.
You'll probably see Ez-download 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 view the digital signature details for Ez-download with the following steps:
Here is a screenshot of a file signed by Ez-download:

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 Ez-download and that no one has tampered with the file.
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, and so on. You can also see the address for Ez-download, such as the street name, city and country.
COMODO Code Signing CA 2 has issued the Ez-download certificates. You can also see the details of the issuer by clicking the View Certificate button shown in the screenshot above.
The following are the Ez-download files I've collected, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 5/45 | firefox_downloader.exe |
Here's the detection names for the Ez-download files. I've grouped the detection names by each scanner engine. Thanks to VirusTotal for the scan results.
| Scanner | Detection Names |
|---|---|
| ESET-NOD32 | a variant of Win32/Toolbar.MyWebSearch.S |
| Ikarus | Win32.SuspectCrc |
| Kingsoft | Win32.Troj.Generic.a.(kcloud) |
| Malwarebytes | PUP.Optional.Downloadster |
| TrendMicro-HouseCall | TROJ_GEN.F47V0829 |
The detection percentage is based on the fact that I've gathered 45 scan results for the Ez-download files. 5 of these scan results came up with some sort of detection. You can review the full details of the scan reports by examining the files listed above.
The analysis is based on certificates with the following serial numbers: