The link is legitimate.
Unfortunately, I don’t know how to help you on this subject other than suggesting to try to figure out how this happened, if your computer might be infected and to use a hardware wallet in the future in case you hold an amount of ADA that you will mind if you lose it. 
Unfortunately there are many attack vectors against wallet software, and a hardware wallet might be the best solution in terms of ease of use and enhanced security.
If your computer is infected maybe you downloaded a fake Daedalus while still visiting the correct link. If you still have the installer you can validate this by following the instructions from the Daedalus website. I’ll paste it here, as if your computer is infected it may not display the correct checksums.
This is just one step in figuring out what happened.
Of course there are many more attack possibilities like key loggers, dictionary brute force attacks against weak spending passwords, etc.
Hi sir, thank you for this and your time. I’ll try to do this one and look for more options.
