Worms are a bigger weakness to Internet security than viruses because of the way they operate. Worms are a subtype of viruses. However, a worm does not need a host in order to replicate. After installation, a worm can spread on its own to another system or through the network without any human intervention. It specifically replicates through networks. They are designed to replicate and spread. If a system is on a network, once it is infected, the worm will immediately begin replicating itself and start spreading itself to other systems on the network. A worm does not modify a stored program like a virus. It exploits program code, applications, operating systems, and protocols. Code Red is a worm for Windows operating systems that first appeared in 2001 and received media attention because of its destructive power. Code Red randomly selected hundreds of IP addresses to see if they were vulnerable. It defaced HTML pages on the local web server and planted a logic bomb that would initiate a denial-of-service (DoS) attack against the IP address 18.104.22.168. The IP address 22.214.171.124 belonged to the web server hosting the home page for the White House. The patch for the vulnerability that Code Red exploited was made available by Microsoft more than a month before Code Red was released.