摘要:
A system for generating a parser and using the parser to parse a target file includes a target file description, an output format description, a Parser generator, a Parser, a target file, and a result object. The target file description and the output format description are included in one or more “properties files”, which are text files that include one or more name/value pairs (“properties”). The target file description and the output format description are input into the Parser generator, which outputs the Parser. The target file is input into the Parser, which outputs the result object. The target file description specifies one or more parsers and/or tokenizers that can be used to parse the target file. The parsers and/or tokenizers specified by the target file description are part of the generated Parser. These parsers and/or tokenizers make the Parser more flexible, which enables the Parser to parse semi-structured data.
摘要:
A logging system includes an event receiver and a storage manager. The receiver receives log data, processes it, and outputs a column-based data “chunk.” The manager receives and stores chunks. The receiver includes buffers that store events and a metadata structure that stores metadata about the contents of the buffers. Each buffer is associated with a particular event field and includes values from that field from one or more events. The metadata includes, for each “field of interest,” a minimum value and a maximum value that reflect the range of values of that field over all of the events in the buffers. A chunk is generated for each buffer and includes the metadata structure and a compressed version of the buffer contents. The metadata structure acts as a search index when querying event data. The logging system can be used in conjunction with a security information/event management (SIEM) system.
摘要:
A unique identifier is assigned to a network node and is used to obtain an “asset model” corresponding to the node and to determine whether the node is a member of a particular category. An asset model is a set of information about a node (e.g., the node's role within the enterprise, software installed on the node, and known vulnerabilities/weaknesses of the node). An identifier lookup module determines a node's identifier based on characteristics of the node (such as IP address, host name, network zone, and/or MAC address), which are used as keys into lookup data structures. A category lookup module determines whether a particular node is a member of (i.e., within) a particular category using a transitive closure to model the categories (properties) that can be attached to an asset model. A transitive closure for a particular asset category is stored as a bitmap, similar to bitmap indexing.
摘要:
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.
摘要:
A network security system having a hierarchical configuration is provided. In one embodiment the present invention includes a plurality of subsystems, where each subsystem includes a plurality of distributed software agents configured to collect security events from monitor devices, and a local manager module coupled to the plurality of distributed software agents to generate correlated events by correlating the security events. Each of the subsystems can report the correlated events to a global manager module coupled to the plurality of subsystems, and the global manager module can correlate the correlated events from each manager module.
摘要:
An “unstructured event parser” analyzes an event that is in unstructured form and generates an event that is in structured form. A mapping phase determines, for a given event token, possible fields of the structured event schema to which the token could be mapped and the probabilities that the token should be mapped to those fields. Particular tokens are then mapped to particular fields of the structured event schema. By using the Naïve Bayesian probability model, a “probabilistic mapper” determines, for a particular token and a particular field, the probability that that token maps to that field. The probabilistic mapper can also be used in a “regular expression creator” that generates a regex that matches an unstructured event and a “parameter file creator” that helps a user create a parameter file for use with a parameterized normalized event generator to generate a normalized event based on an unstructured event.
摘要:
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.
摘要:
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.
摘要:
A selected time interval of previously stored security events generated by a number of computer network devices are replayed and cross-correlated according to rules defining security incidents. Meta-events are generated when the security events satisfy conditions associated with one or more of the rules. The rules used during replay may differ from prior rules used at a time when the security events occurred within a computer network that included the computer network devices. In this way, new rules can be tested against true security event data streams to determine whether or not the rules should be used in a live environment (i.e., the efficacy of the rules can be tested and/or debugged against actual security event data).
摘要:
Device discovery can be made efficient using certain embodiments of the present invention. In one embodiment, the present invention includes accessing a message in a message log, wherein the message log associates a host identifier with the message, the host identifier being an identifier of a host that sent the message to the message log. Then a list of parsers associated with the host identifier associated with the message can be accessed and parsing the message using parsers from the list of parsers associated with the host identifier can be attempted. If the parsing is unsuccessful, a device type of an originator of the message can be discovered, and a parser associated with the discovered device type can be added to the list of parsers associated with the host identifier.