If you did not intend to come to this page, but instead wanted to go to Google, Yahoo, etc. and wound up here, then your Internet Service Provider's (ISP) Domain Name Systems (DNS) servers have been attacked by parties unknown.
You should contact your ISP and tell them they need to fix their DNS servers. MIT and the operator of this server have nothing to do with the attack, like you, we are victims.
IMPORTANT: This tool works by sending a series of UDP packets with different port numbers and TTL (Time To Live). If you are running firewall software, your software may interpret the incoming packets as a hostile "port scan" originating from this server (jis.mit.edu). Rest assured, your system is not being attacked.