I found some people are doing that in different ways. Yesterday, I have visited a IEO group and asked for attention from admin. Couple of minutes later, someone knocked me and started to ask if I want to invest? He claimed he is an admin of that IEO group. I checked his profile and the admin from the group. For a moment I was fool. The scammer who knocked me was using the username of the original admin, in his (scammer) bio profile.
But, I further looked and got the different.
Don't send any fund if anyone ask you, no real project's admin will PM you.
That is true, scammers are basically on all telegram group, the more popular some project is, more scammers will try to trick you.