Ports being blocked repeatedly every minute

Since lastnight at 8 PM Norton's been showing weird activity. At least 1-20 times per minute I'd see this:

 

Rule "Default block SSDP" blocked (ip, port (2869) ) Inbound TCP connection.

 

I'd see dozens of these every minute and they wouldn't go away no matter what I was doing, unless I went offline. They just started randomly appearing when I wasn't  using my computer. I tried to do some research but didn't get any peace of mind because it seems too suspicious. I turned on my computer this morning and I'm seeing a different message at the same frequency:

 

Rule "Default block UPnP Discovery" stealthed (ip, Port ssdp(1900) ) Inbound UDP packet.

 

The first one had a lot of processes using it like System, lsass.exe, and Services.exe. The second one keeps coming from Svchost.exe.

 

I haven't changed anything to my computer or downloaded anything different. When this started happening I wasn't using my computer. It's never happened before and most of what I searched for didn't really help. It's really concerning because it's filled up 1/4 of my entire activity for Norton now. I'd appreciate any help. Thanks.