Abstract: A method for detecting malicious packets includes comparing a sequence number of an input packet with sequence numbers of one or more previously input packets and detecting a malicious packet when the sequence number of the input packet matches at least one of the sequence numbers of the previously input packets.

Abstract: A method for detecting malicious programs within a network, includes monitoring at least one packet within the network to ascertain a source address and a destination address of the at least one packet, determining whether the source address and the destination address of the at least one packet match addresses within a listing of addresses of devices on the network and generating an alert when neither the source address nor the destination address of the at least one packet match addresses within the listing of addresses of devices on the network.

Abstract: A method for maintaining computer security comprises receiving an incoming email destined for an email server, determining whether the received incoming email is infected with malicious code and blocking the incoming email determined to be infected with malicious code from reaching the email server.

Abstract: A method for maintaining computer security, includes providing a database of known good software, opening a file, identifying the file being opened, determining whether an entry exists in the database of known good software for the identified file and performing at least one of allowing and preventing the opening of the file from continuing based on the result of the determination.

Abstract: A method for displaying an alert log including one or more alerts, the method including prioritizing the one or more alerts according to an importance of each of the one or more alerts and displaying the one or more alerts according to the priority.

Abstract: A method and system for maintaining computer security including providing a signature file; receiving an incoming message from at least one client computer; comparing the received incoming message with the signature file to determine whether the incoming message is malicious; and blocking the incoming messages determined to be malicious from reaching a web server.

Abstract: A method of identifying a plurality of nodes on a network, includes receiving at at least one of the plurality of nodes on the network a query posed by a caller node determining at the at least one of the plurality of nodes on the network an answer to the query, forwarding the answer to the query from the at least one of the plurality of nodes on the network to the caller node and receiving, at the caller node, the answer to the query from the at least one of the plurality of nodes on the network and maintaining a list of nodes which responded to the query.