If you are at an office or shared network, you can ask the network administrator to run a scan across the network looking for misconfigured or infected devices. What can I do to prevent this in the future? Get a chance to have your trade featured for 5 minutes!
HERE's PROOF You do not get a key simply by inviting friends, you get a chance to win depending on how many friends you invited. Once verified, you will automatically proceed. This is so our server knows where to send the CS GO Steam Key.