Presumably you weren't trying to connect to that site ?
If not start by clearing your browser cache and cookies,including 3rd party cookies and restart your browser.
If that resolves it you should be good to go.
If it doesn't try running your browser with add-ons disabled.
If that resolves it, have you added or updated any add-ons ?
If so try disabling that add-on - and restart and try again.
If still not resolved and you are using Chrome based browser - try this suggest by Avast Team member 'lukor'
What about page notifications? Here: chrome://settings/content/notifications ? Do you have all cleared?
It is a good sign if you weren't intending to visit this site:
Nondescript domains like this may well be suspect.
See this analysis at Virus Total -
https://www.virustotal.com/gui/url/dc4e4981fdcf66dd5aa5598f6b8d224f475ed7e40d8564d7a9fef43c767fcaf0?nocache=1Also look at the Details and Comments sections,in the above link - it certainly looks suspect.