Some manner of spam texter sent out a message to my entire family. Whatever that link is, I'm not clicking it.

Just got one too!

Got a text a few hours ago, it was blank. Didn't reply.

AS ONLY MY FAMILY HAVE THIS # ..IT IS HARD FOR ME TO FIGURE OUT HOW THE SPAMMER GOT THE # ...MY MESSAGE READS... HI  THIS IS sarah (in small letters) talk to me on www.mobidescription.com

First you can forward all text message spam to 7726 to let your carrier squash the maggots.  Second, they didn't "get" you number anywhere.  They use an app to generate their text spam and send it to every number in a given area code and exchange in sequence.  Whatever you do, never click on links in messages from unknown senders, don't even bother texting back to try and find out who they are.