What will likely happen after you deposited the scanned check is that the check will bounce after a couple days because it's either not covered or because it siis from someone else's account. The money in your account will then go back to where it came from.
But that alone doesn't get the scammer anything. Possible ways the scammer could benefit from this:
- Scam you out of goods or services. Whatever you expected to get paid for, you don't.
- Advanced fee fraud. Get you to pay money in order to receive and cash the check.
- Abusing you as a money mule. After you got the money they ask you to send part of the money back to them in a way which can not be as easily reverted. The check gets reverted but your payment doesn't.