Looks like another spam hijacking. Do not open any message that has no proper subject line, and no text - just a link.
I am seriously considering making the entire group "moderated", as each time someone's e-dentity is hijacked and a bogus message is posted, there is a very real threat to everyone else that is created. Deleting the message and putting the e-dentity on moderated status may not be effective enough of a reaction - too little, too late?
The down-side of making the list a 100% moderated one is that it slows down the discussion. However, the number of incidents hence the risk to group members, seems to be increasing...