With the growing deployment of host and network intrusion detection systems, managing reports from these systems becomes critically important. We present a probabilistic approach to alert correlation, extending ideas from multisensor data fusion. Features used for alert correlation are based on alert content that anticipates evolving IETF standards. The probabilistic approach provides a unified mathematical framework for correlating alerts that match closely but not perfectly, where the minimum degree of match required to fuse alerts is controlled by a single configurable parameter. Only features in common are considered in the fusion algorithm. For each feature we define an appropriate similarity function. The overall similarity is weighted by a specifiable expectation of similarity. In addition, a minimum similarity may be specified for some or all features. Features in this set must match at least as well as the minimum similarity specification in order to combine alerts, regardless of the goodness of match on the feature set as a whole. Our approach correlates attacks over time, correlates reports from heterogeneous sensors, and correlates multiple attack steps.

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Probabilistic Alert Correlation

A system and method provide comprehensive and highly automated testing of vulnerabilities to intrusion on a target network, including identification of operating system, identification of target network topology and target computers, identification of open target ports, assessment of vulnerabilities on target ports, active assessment of vulnerabilities based on information acquired from target computers, quantitative assessment of target network security and vulnerability, and hierarchical graphical representation of the target network, target computers, and vulnerabilities in a test report. The system and method employ minimally obtrusive techniques to avoid interference with or damage to the target network during or after testing.

System and method for network vulnerability detection and reporting

The disclosure is directed to a sensor device including processing circuitry, at least one sensor coupled to the processing circuitry, a serial data interface coupled to the processing circuitry and memory responsive to the processing circuitry. The memory includes a static unique identification number. The serial data interface provides access to retrieve the static unique identification number and sensed data measured with the at least one sensor from the memory.

Environmental monitoring device

The present invention is directed to systems and methods for detecting unsolicited and threatening communications and communicating threat information related thereto. Threat information is received from one or more sources; such sources can include external security databases and threat information data from one or more application and/or network layer security systems. The received threat information is reduced into a canonical form. Features are extracted from the reduced threat information; these features in conjunction with configuration data such as goals are used to produce rules. In some embodiments, these rules are tested against one or more sets of test data and compared against the same or different goals; if one or more tests fail, the rules are refined until the tests succeed within an acceptable margin of error. The rules are then propagated to one or more application layer security systems.

Systems and methods for message threat management

A method of describing intrusion signatures, which are used by an intrusion detection system to detect attacks on a local network. The signatures are described using a “high level” syntax having features in common with regular expression and logical expression methodology. These high level signatures may then be compiled, or otherwise analyzed, to provide a process executable by a sensor or other processor-based signature detector.

Intrusion detection signature analysis using regular expressions and logical operators

In one aspect of the invention, a computer implemented method for rules-driven multi-phase network vulnerability assessment is disclosed. The method comprises pinging devices on a network to discover devices with a connection to the network. Port scans are performed on the discovered devices and banners are collected. Information from the collected banners are stored as entries in a first database. Analysis is performed on the entries by comparing the entries with a rule set to determine potential vulnerabilities. The results of the analysis are stored in a second database.

System and method for rules-driven multi-phase network vulnerability assessment

Various embodiments of a method and system for detecting unauthorized signatures to or from a local network. Multiple sensors are connected at an internetworking device, which can be a router or a switch. The sensors operate in parallel and each receives a portion of traffic through the internetworking device, at a session-based level or at a lower (packet-based) level. Depending on the type of internetworking device (router or switch) the load balancing mechanism that distributes the packets can be internal or external to the internetworking device. Also depending on the level of packet distribution (session-based or packet-based), the sensors share a network analyzer (if session-based) or both a network analyzer and a session analyzer (if packet-based).

Parallel intrusion detection sensors with load balancing for high speed networks

A system and method are disclosed for real-time insertion of data into a multi-dimensional database. The system includes a multi-dimensional database and a user interface operable to access and provide views into the multi-dimensional database. A data insertion engine is coupled to and operable to access the multi-dimensional database. The data insertion engine is further operable to receive and process a real-time data feed and to insert data into the multi-dimensional database responsive to processing of the real-time data feed. In one embodiment, the real-time data feed can represent exploited network vulnerabilities, and the system can be used for network intrusion detection and vulnerability assessment. The method includes receiving a real-time data feed representing detection of an event and processing the event against the multi-dimensional database. Cells associated with the event are identified in the multi-dimensional database and appropriate vectors to the identified cells are created. Data representing the event is then inserted at the identified cells. Visibility to the inserted data is provided through a user interface to the multi-dimensional database. In one embodiment, the event can be an exploited network vulnerability, and the method can be used for intrusion detection and vulnerability assessment.

System and method for real-time insertion of data into a multi-dimensional database for network intrusion detection and vulnerability assessment

A method of detecting signatures representing misuse of a local network. Known reference signatures having one or more common events are identified, and represented with a decision graph having one or more shared nodes. Each node of the decision graph represents the occurrence of an event. Given a set of input events, test functions associated with nodes determine the path taken during traversal of the graph. A path of the graph from the parent node to a leaf node represents the occurrence of all events that comprise a signature. The decision graph permits any of the signatures to be detected with only one traversal, and avoids the need for a separate matching process for each signature. In this manner, an entire set of all known reference signatures may be consolidated into a smaller set of decision graphs.

Steven D. Shanklin

Papers

Intrusion detection signature analysis using regular expressions and logical operators

System and method for rules-driven multi-phase network vulnerability assessment

Parallel intrusion detection sensors with load balancing for high speed networks

System and method for real-time insertion of data into a multi-dimensional database for network intrusion detection and vulnerability assessment

Network intrusion detection signature analysis using decision graphs