As normally VT does not detect one thing. Killmallware has it: http://killmalware.com/opensch.org/
Quttera has it: http://quttera.com/detailed_report/www.opensch.org
and Sucuri has it too: Web site defaced. Details: http://sucuri.net/malware/entry/MW:DEFACED:01
<-font color="black">HACKED By : ♥ 3L-MUH4J1M1 ♥<-/font>
This signature was found in 265 websites.WordPress Version
3.4.1
Version does not appear to be latest 4.4 - update now.
See: http://toolbar.netcraft.com/site_report?url=http://www.opensch.org
polonus