Scammers rent a real apartment and pretend to be the tenant or landlord. They show you the apartment, sign a lease, collect the deposit and rent, and even give you keys. When you move in, the keys don’t work because they never had the right to rent out the apartment. The scammers disappear with your money.
This scam is very hard to detect because the apartment, documents, and keys are all real.
How to avoid it: Look for signs of a vacation rental (such as a key safe), use reverse image search to check if the apartment is listed on Airbnb or other rental sites, and ask neighbours who actually lives there.