Abstract:
Example network monitoring methods disclosed herein include iteratively adjusting respective weights assigned to respective types of network activity features for devices monitored in a network, the iterative adjusting to determine an output set of weights corresponding to ones of the types of network activity features indicative of malicious network activity. For example, the iterative adjusting is to (1) reduce a first distance calculated between a first pair of reference devices previously classified as being associated with malicious network activity, and (2) increase a second distance calculated between a first one of the pair of the reference devices and a first unclassified device. Disclosed example network monitoring methods also include determining whether a second unclassified device is associated with malicious network activity based on the output set of weights.
Abstract:
Anomalies are detected in a network by detecting communication between a plurality of entities and a set of users in the network, determining an overlap between subsets of the set of users that the entities comprising the plurality of entities communicated with, respectively, and determining whether the communication between the plurality of entities and the set of users is anomalous based on the overlap.
Abstract:
A method of generating a signature for a group of electronic messages that each include a plurality of characters comprises extracting a plurality of blocks of characters from each of the electronic messages, mathematically processing each of the blocks of characters from each electronic message, and generating a signature for the group of electronic messages based at least in part on the mathematically processed blocks of characters. In some embodiments a counting Bloom filter may be used to generate the signature. The signatures generated by these methods may be used to identify spam.
Abstract:
Methods, apparatus, systems and articles of manufacture are disclosed to identify an Internet protocol address blacklist boundary. An example method includes identifying a netblock associated with a malicious Internet protocol address, the netblock having a lower boundary and an upper boundary, collecting netflow data associated with a plurality of Internet protocol addresses in the netblock, establishing a first window associated with a lower portion of Internet protocol addresses numerically lower than a candidate Internet protocol address, establishing a second window associated with an upper portion of Internet protocol addresses numerically higher than a candidate Internet protocol address, calculating a breakpoint score based on a comparison between a behavioral profile of the first window and a behavioral profile of the second window, and identifying a first sub-netblock when the breakpoint score exceeds a threshold value.
Abstract:
Methods, apparatus, systems and articles of manufacture are disclosed to learn malicious activity. An example method includes assigning weights of a distance function to respective statistical features; iteratively calculating, with a processor, the distance function to adjust the weights (1) to cause a reduction in a first distance calculated according to the distance function for a first pair of entities in a reference group associated with malicious activity and (2) to cause an increase in a second distance calculated according to the distance function for a first one of the entities included in the reference group and a second entity not included in the reference group; and determining whether a first statistical feature is indicative of malicious activity based on a respective adjusted weight of the first statistical feature determined after calculating the distance function for a number of iterations.