Cisco IronPort Blacklisting Samsclass.info

I have been invited to teach some workshops in Houston. However, the people promoting them informed me that potential students are unable to examine my class materials because their corporate security device blocks my website. Here's the message they see:

Provided by ECDCIronPortC
Date: Thu, 28 Jan 2016 16:15:41 GMT
Username: REDACTED@Active_Directory
Source IP: REDACTED
URL: GET https://samsclass.info/128/HCC_16.shtml
Category: Computers and Internet
Reason: BLOCK-MALWARE
Threat Type: othermalware 
Threat Reason: Domain reported and verified as serving malware. Identified as malicious domain or URL. 
Notification: WBRS

How rude! My site is not hosting malware. It passes the tests listed below. Why is Cisco blocking my site?

Sucuri SiteCheck

https://sitecheck.sucuri.net/results/samsclass.info

McAfee SiteAdvisor

https://www.siteadvisor.com/sites/samsclass.info

Google Safe Browsing

https://www.google.com/transparencyreport/safebrowsing/diagnostic/#url=samsclass.info

Qualys SSL Test

https://www.ssllabs.com/ssltest/analyze.html?d=samsclass.info

Posted 1-29-15 12:39 pm by Sam Bowne