I and my friend encountered this situation and I am sure many others would have too. Scammers contact the crypto users on telegram. They get your ID from crypto related telegram channels and then ask you for a help. The scammer tells you that he is not able to withdraw coins from an exchange and asks you help him by signing up on the exchange and withdrawing coins from there to the scammers address. In return they give you a few amount of bitcoins.
The scammers website asks you to deposit at least 0.01btc before you can withdraw any coins. People fall for this trap and hence get scammed.
Few of such sites built by the scammers: westcrypt.info , monocrypt.info , cryptoelips.com , westerncrypt.com
Find the discussion from various other people here:
https://forums.digitalpoint.com/threads/new-scam-site-danger.2842061/Be aware guys. Do not fall for such traps.
This is very common scam on internet, aside to this some people contact you directly and claim that they from some big exchange, that particular exchange is running an airdrop of giving first 100 people 5 times of 10 times ETH, means you deposit 1 ETH and they give you 5 ETH on the same address, people fall for it and lose their 1 ETH.
Other to this some scammers create a Telegram channel with some famous names like "Binance and Ethereum partnership" and give you some free airdrop, some people on such channels keep on writing that they received their reward, these all are scammers, pls be aware of them.