Abstract: The present disclosure is directed to methods and systems for malware detection based on environment-dependent behavior. Generally, an analysis environment is used to determine how input collected from an execution environment is used by suspicious software. The methods and systems described identify use of environmental information to decide between execution paths leading to malicious behavior or benign activity. In one aspect, one embodiment of the invention relates to a method comprising monitoring execution of suspect computer instructions; recognizing access by the instructions of an item of environmental information; identifying a plurality of execution paths in the instructions dependant on a branch in the instructions based on a value of the accessed item of environmental information; and determining that a first execution path results in benign behavior and that a second execution path results in malicious behavior.

Abstract: The present disclosure is directed to methods and systems for reciprocal generation of watch-lists and traffic models characteristic of malicious network activity. In some aspects, the described methods and systems relate to maintaining data for recognition of malicious network activity. In general, the methods include monitoring network traffic; comparing endpoint data from monitored data packets to endpoints in a watch-list of network endpoints and comparing packet data from monitored data packets to traffic models in a catalog of traffic models characterizing malicious network activity; and determining, based on the comparisons, that a set of data packets comprise suspect network activity. The methods include adding a network endpoint to the watch-list when the determination is based on comparing packet data to a traffic model or adding a traffic model to the catalog when the determination is based on comparing endpoint data.

Abstract: The present disclosure is directed to methods and systems for reciprocal generation of watch-lists and traffic models characteristic of malicious network activity. In some aspects, the described methods and systems relate to maintaining data for recognition of malicious network activity. In general, the methods include monitoring network traffic; comparing endpoint data from monitored data packets to endpoints in a watch-list of network endpoints and comparing packet data from monitored data packets to traffic models in a catalog of traffic models characterizing malicious network activity; and determining, based on the comparisons, that a set of data packets comprise suspect network activity. The methods include adding a network endpoint to the watch-list when the determination is based on comparing packet data to a traffic model or adding a traffic model to the catalog when the determination is based on comparing endpoint data.