I'm not sure who is behind this humor site/FB/twitter identity, but their stories and tweets ("New Islamist State jihadist accidentally packs wrong black flag") are not bad. This 'apology' to the PR firm Bell Pottinger is kind of classic, as well:
Bell Pottinger's response is obtuse:
27 August 2014
Bell Pottinger has not been hired by the Islamic State
Bell Pottinger would like to make it absolutely clear we have not been hired to do the public relations for the Islamic State (IS, formerly ISIS). A so-called satirical website, The Pan Arabian Enquirer, ran a story that we had been hired by IS the other day. It has since been deleted.
Tim Bell said: "I am surprised that any publication or journalist would think the subject of IS, who recently beheaded the American journalist James Foley, was an appropriate subject for humour or satire".