Abstract: The present invention relates to a system and a method for preventing an attack of a malicious program spread using a web technology comprising a malicious code distribution site detection server comprising a malicious code distribution site detector for detecting a malicious code distribution site, and a prevention message transmitter for transmitting a prevention message to a routing configuration server, wherein the prevention message includes an IP address of the malicious code distribution site detected by the malicious code distribution site detector; a plurality of routers including a virtual IP address; and the routing configuration server for advertising the IP address of the malicious code distribution site such that a routing path of a packet having the IP address of the malicious code distribution site as a target address or an starting address is guided to the virtual IP address according to an reception of the prevention message to block a connection to the malicious code distribution site.