Avast Users can't see my site, says "Trojan Horse"

Having an issue where some users (so far all of them Avast users) are blocked from seeing my site at all or it reads “You’ve been blocked from a trojan horse.” My site is database driven Wordpress site and pretty big. It’s also updated and protected by two firewalls, so I’m having a hard time figuring out what is causing this error. Here is the link:
http://undergroundrailroadhistory.org

Any insight is super appreciated!

http://sitecheck2.sucuri.net/results/undergroundrailroadhistory.org/

VirusTotal - undergroundrailroadhistory.org.htm
https://www.virustotal.com/nb/file/5b14884fca5d17e6418a87937774022429ea045f7fd65daa3e4162ff38feb585/analysis/1394212438/

sucuri blog HideMe spam http://blog.sucuri.net/?s=hideme+spam