I'm confused - you find a random private key on the internet and decide to send btc to the wallet? I thought that with the private key you can just load up a new wallet, input the private key, and now you can sign transactions for that wallet and send the transactions to the blockchain. What do you get out of sending the btc to the wallet, or am I being dumb and what you did made sense?
Counterparty and it's assets (SJCX, DTB, COVAL, PEPE, etc.) don't have their own unique blockchain, but rather embed data into Bitcoin's blockchain. They ride along BTC transactions if that helps. As a result, you send Counterparty assets to a BTC address, but in order to transfer them from the wallet you need some BTC in the wallet as well to cover the network fees. This wallet has XCP/EGOLD in it but no BTC, so in order to sweep the former you need to send a bit of the latter. You need .001224 BTC to remove both the EGOLD and XCP or .000356 BTC for only the XCP. You can also enter the private key of a Bitcoin address and attempt to sweep it that way, but I don't want to try it.
Here's the public key if you want to check out the contents at counterwallet.io: 1DxzwX4qC9PsWDSAzuWbJRzEwdGx3n9CJB.
It's a pretty brilliant way to scam small amounts of money off unsuspecting people. You really can't even be that mad at the guy who created it as you were trying to take the goods from a wallet that wasn't yours in the first place.