Your PC hasn't been attacked but the server which hosts the website of that property company has.
M3rhametsiz is a prolific hacker who attacks large numbers of websites, the majority of which seem to be UK based. To see a list of his latest successes, see here:
http://www.zone-h.org/component/option,com_att acks/Itemid,43/filter_defacer,m3rhametsiz/
The hacked website displays content chosen by the hacker (such as the panther's head) but it shouldn't present any threat to your own PC. Even if the hack succeeded in placing viruses, trojans or other 'nasties' on the hacked site (which most hackers wouldn't even try to do), your firewall and/or anti-virus software should have prevented it transferring to your PC.
Chris