Sometimes, they ask you for personal information like your name, address, telephone No, mobile, etc. Others, which are highly professionals asking you for a passport scans and your bank account...
I believe they will not steal you, however they may get in you a really hard trouble..

I have got a lot of this scams from people in Nigeria...who have tons of millions and need someone to help them transferring their money out...

Regards,

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"Did ye then think that We had created you in jest, and that ye would not be brought back to Us (for account)?"

Surah "Al Mo'Emnon" verse (115)
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