This is might be true bec qatar foundation is one of the high paying organizations here in qatar. don't disclose your package here.
I was hired also through online application too (not by Qatar Foundation). Got picked and interviewed and was invited for 4 days 3 nights stay in Qatar all expenses paid including hotel accommodation with buffet meals (breakfast, lunch & dinner). Then it took me almost 2 months to finally join the company since i have to take medical exam and process all the requirements that must be authenticated locally and here in Qatar via DHL. All my expenses in processing my papers were reimbursed together with the extra luggage charge from the airline as it was stipulated in the contract.
you may verify if the offer is true by checking their website and their contact number. You may directly email qf or call their personnel to answer your doubts. I do hope that's a genuine offer. Good luck!