Wait, what?
First of all, blockland doesn't require port forwarding anymore.
Second of all, a direct attack to your router would be next to impossible. He'd have to connect through your PC (Blockland does not serve as a gateway for this) to your router, get past your password lock, un-port forward the ports, log out, close the connection to your PC. Now, I'm not saying this is impossible, but it'd take a very skilled hacker to do this and I highly doubt k1lla4l1f has the skills to do it. Even so, he'd have to make you download something which I highly doubt you would.