In general if any job offer includes free accommodation, free flights, free food , a large salary with additional benefits and guarantees a work permit specifically by a certain date then you should consider that is a fake job offer. There are many people who operate almost as a business offering fake jobs where they even create fake websites to try and convince people that a company offer is genuine. If ever any doubt come back to this forum and there are plenty of people who will help confirm whether genuine or not.