I just got an "Infection Blocked" alert from Avast when I went to the Macworld site - 8:40 pm eastern timeAug 2nd From a macworld URL ending in . . . ads/prebid.min.js.  

Is this something to be worried about? Should this be reported to someone?
Prebid is a program on the server that serves the site, it is used to setup and manage header bidding advertising partners without writing code or confusing line items. For more on the project, see https://github.com/prebid/Prebid.js — basically, if there are ads on the site, it’s trying to block them from being interactive.