Scammers look out for possible victims within popular messenger groups and search for users who allow direct communications. In some cases, the scammers imitate admins of groups where they found the user in. In other cases, the scammers sent promotional messages which promise great deals, and which are linking to fake websites.
Avoid / turn off direct messages / Ingore strangers
Investors, who use messenger apps, should use restricting settings. Users should never trust anyone they do not know and who is contacting them in a private message. Legitimate admins of real projects will never send a direct message first.