I think it's been speculated that this company could do it:
http://www.roland-lb.com/
Hezbollah is not likely to tell us who they hired.
Thank you - most likely is was this company who printed it. They have the printers to do it in less than 1 hour.
up to 104" wide (just over 8 and a half feet)...that poster is at least 12 feet wide. It also does that relatively narrow strip at 484 sq ft/hr at lowest resolution of 360 dpi... and a maximum roll weight of 220 lbs.
print speed drops off dramatically with higher resolutions. (the printer on the next page http://www.roland-lb.com/printing_1.htm can get up to 75 sq ft/min at 720*720, in bidirectional mode.