Don’t know if reef is a scam but its founder Denko Mancheski has a history of scams and rug pulls.
https://18digits.com/r-cryptocurrencies-reef-finance-from-an-investor-to-accuser/

Reef (REEF) - USDT
₮ 0.0005491
Just now
-2.56%
Mkt. Cap.
₮ 12.53 M
Vol. 24H
REEF 1.84 B
(₮ 1.01 M)
Open 24h
₮ 0.0005636
Low/High 24h
₮ 0.0005300
-
₮ 0.0005646