Hi Telmo, I understand what you mean, and you have no worries or risks using/installing these software or any other particular software listed here.
We thoroughly check all software for malware and virus before adding them to the database. At times, anti-virus applications can overreact. So, you can rest assured that these are safe/reliable to use.
If you have any further issues, just let us know and we can take a look into this for you.
i have used them lots of times, in fact its not just the video sites it will also flag some of the other exe products will. Windows looks for security certificate and if it does not find it you get the warning.