Very good question indeed. For me it took 35 years to be able to recognise it, so I can only give some clues. 1) Such people keep taking more and information about you, your personal life but never actually solves any of them instead may create hurdles on your path through some other person known to you. 2) They begin with talking negative about others. 3) They keep promoting people or products in every meeting so that they can earn something because they spent time with you, but they do it in such a manner that it looks like they are helping you. 4) They fix their next meeting with you before departing.
Hope it will be of some help, with lots of blessings.
Now my question How you come to know if one is really spiritually enlightened?