摘要:
A communication between an entity and a host is identified. Reputation information associated with a set of other entities that communicate with the host is identified. A reputation score associated with the host is generated based on the reputation information associated with a set of other entities. A reputation score associated with the entity is generated based on the reputation score associated with the host.
摘要:
A computer generates a reputation score for a file based at least in part on the lineage of the file. A security module on a client monitors file creations on the client and identifies a parent file creating a child file. The security module provides a lineage report describing the lineage relationship to a security server. The security server uses lineage reports from the client to generate one or more lineage scores for the files identified by the reports. The security server aggregates the lineage scores for files reported by multiple clients. The aggregated lineage scores are used by the security server to generate reputation scores for files. The reputation score for a file indicates a likelihood that the file is malicious. The security server reports the reputation scores to the clients, and the clients use the reputation scores to determine whether files detected at the clients are malicious.
摘要:
Techniques for classifying unknown files taking into account temporal proximity between unknown files and files with known classifications are disclosed. In response to a classification request for a target file, client systems hosting (or hosted) instances of the target file are identified. For each system, files created around the time the target file was created on the system are identified. Within the identified files, files with known classifications are identified, and a score is determined for each such file to measure temporal proximity between the creation of the file and the creation of the target file. Local temporal proximity scores aggregate the scores for the client system. Global temporal proximity scores measures an aspect of the local temporal proximity scores for all identified client systems. The global temporal proximity scores are fed into a classifier to determine a classification, which is returned in response to the classification request.
摘要:
An enterprise network can have sanctioned and unsanctioned servers on it. Sanctioned servers are approved by an administrator and perform tasks such as web page serving and mail routing. Unsanctioned servers are not approved by the administrator and represent possible security risks. A service monitor accesses one or more metadata sources having information describing the enterprise network, such as domain name system (DNS) records on the Internet. The service monitor analyzes the metadata and creates a security profile for the enterprise network. The security profile identifies the sanctioned servers. The service monitor monitors network traffic for compliance with the security profile, and detects unsanctioned servers on the network. The service monitor reports violations of the profile and informs the administrator of the unsanctioned servers.
摘要:
A reputation server is coupled to multiple clients via a network. Each client has a security module that detect malware at the client. The security module computes a hygiene score based on detected malware and provides it to the reputation server. The security module monitors client encounters with entities such as files, programs, and websites. When a client encounters an entity, the security module obtains a reputation score for the entity from the reputation server. The security module evaluates the reputation score and optionally cancels an activity involving the entity. The reputation server computes reputation scores for the entities based on the clients' hygiene scores and operations performed in response to the evaluations. The reputation server prioritizes malware submissions from the client security modules based on the reputation scores.
摘要:
An access control system (200) enables a computer network (1) to prevent execution of computer code that may contain computer viruses. An access control console (201) generates an access control message (260) including control parameters such as a time limit (255). Said time limit (255) is disseminated to computers (2, 3) on the network (1). Said computers (2, 3) use the time limit (255) to determine the executability of computer code. Access control system (200) also enables blocking data communications with suspicious or susceptible programs in network (1) during virus outbreaks.
摘要:
Methods, systems, and computer readable media for managing transmission of a requested computer file (140) from a remote host compute (125) to a client computer (120). A proxy server computer (110) receives a first chunk (315) of the requested computer file (140). The proxy server (120) generates a hash of the chunk (315) and compares the hash to a hash of a chunk of previously downloaded file. If the two hashes are identical, the chunk (315) of the requested computer file (140) is passed to the client computer (120).
摘要:
A computer readable file of a first state (3.0) is updated to a second state (3.2) through the use of an incremental update (112) which provides the information necessary to construct the file of the second version (3.2) from a file of the first version (3.2). In order to allow for future access to the first version (3.0), without maintaining a copy of the file of the first version (3.0), a back-update file (206) is created. The back-update file (206) provides the information necessary to construct a file of the first state (3.0) from a file of the second state (3.2).
摘要:
A computer-implemented method for executing a computer file in a CPU emulator (154) to detect a computer virus. The method includes simulating (302) the execution of a predetermined number of instructions of the computer file in the CPU emulator (154), suspending (303) the execution, constructing (304) a state record, temporarily storing (305) the state record in memory, comparing (306) the constructed state record to state records stored in a state cache (158), and indicating (308) that the file is virus free when the constructed state record matches one of the stored state records.
摘要:
An emulation module (110) includes a pre-fetch queue (116) having an adjustable size (126) to eliminate any dependence of virus decryption routines on the size of the pre-fetch queue (116) when emulating executable files to test for the presence of virus infections. An executable file is tested by setting (210, 258) the size of the emulator's pre-fetch queue (116) and emulating (220) the file under the guidance of an emulation control module (130). Emulated instructions are monitored and a flag is set (230) when any instructions are modified (224) after being copied to the pre-fetch queue and subsequently executed (228). Emulation continues until the emulation control module (130) indicates (230) that the file should be scanned for virus signatures. If no virus signatures are detected (234) and the flag is set (244), the size of the pre-fetch queue is reduced (258) and the process is repeated. An executable file is declared virus-free (250) if the file is emulated (220) without setting the flag (230) and no virus signatures are detected (234). The executable file is declared virus-infected (240) when virus signatures are detected (234), independent of whether the flag is set (230). For Intel processors, pre-fetch queue sizes of 32, 16, 8, and zero bytes may be emulated.