Abstract: Security events generated by a number of network devices are gathered and normalized to produce normalized security events in a common schema. The normalized security events are cross-correlated according to rules to generate meta-events. The security events may be gathered remotely from a system at which the cross-correlating is performed. Any meta-events that are generated may be reported by generating alerts for display at one or more computer consoles, or by sending an e-mail message, a pager message, a telephone message, and/or a facsimile message to an operator or other individual. In addition to reporting the meta-events, the present system allows for taking other actions specified by the rules, for example executing scripts or other programs to reconfigure one or more of the network devices, and or to modify or update access lists, etc.

Abstract: A prefix expression tree showing an expression can be supplemented to also display the expression in infix notation. In one embodiment, the present invention includes displaying an expression being capable of representation in infix and prefix notation in prefix expression tree format. In one embodiment, the expression includes a plurality of operators and operands, and the plurality of operands make up the leaves of the expression tree. In one embodiment, the present invention further includes inserting a plurality of infix operators corresponding with the plurality of operators into the prefix expression tree, wherein, the plurality of operands and infix operators represent the expression in infix notation.

Abstract: A network security system is provided that receives information from various sensors and can analyse the received information. In one embodiment of the present invention, such a system receives a security event from a software agent. The received security event includes a target address and an event signature, as generated by the software agent. The event signature can be used to determine a set of vulnerabilities exploited by the received security event, and the target address can be used to identify a target asset within the network. By accessing a model of the target asset, a set of vulnerabilities exposed by the target asset can be retrieved. Then, a threat can be detected by comparing the set of vulnerabilities exploited by the security event to the set of vulnerabilities exposed by the target asset.

Abstract: In one embodiment, the present invention provides for receiving security events from a network device by a distributed software agent of a network security system, determining a priority of each received security event, and storing the security events in a plurality of prioritized event buffers based on the determined priorities for a period of time determined by a timer. Upon expiration of the timer, a batch of security events for transport to a security event manager of the network security system can be created by including security events in the batch in order of priority until the batch is full.