The phenomena you experienced isn't widespread. Otherwise everyone's AV software would be reporting trouble. It seems to be specifically IE8 users and those who reboot and revisit the site report the threat is no longer there. I suspect it is a random false positive. The website has been inspected by two internet security resources and reported to be clean. These reported warnings effects just the landing page, not the store pages as it is hosted separately. So if you want to shop, use the direct link:
https://store.spruebrothers.com/
I suggest clearing your cookies, as it could be what's triggering the warning when you visited the site. Again, this isn't being experienced by everyone visiting the SB homepage primarily IE8 users...so consider an upgrade to IE9.