Certainly Lnkedin is one of the more representative job search sites because it offers reliable, eloquent and comprehensive facts that describe the job we are interested in. However, I do not know how well this is known, but the hackers have also attacked this site, so that it should be careful. What you need to do immidiately is after contacting the employer, request a video call to talk to him, as if you check through the official website of the company for which you are interested, the details of the job. It's not unusual that when you go through the company's official website they have no idea that an ad for new employees has been published for the job. The official site of the company is much easier to recognize, while on Linkedin it is possible to forge the data from the alleged employer, who is represented as HR manager of the company, and in fact it is not.