Abstract: The subject disclosure relates to antimalware scanning, and more particularly to offline antimalware scanning of a host environment via an alternate, known safe operating system. An offline scanning product obtains data previously written by the host environment online antimalware scanning tool, e.g., configuration data and antimalware signatures in shared data stores accessible to the offline and online products, and uses that data to perform the offline antimalware scan. The offline scanning product writes results information and any quarantined files to other shared data stores, whereby the online environment, when rebooted, has access to the information, such as for review and to upload telemetry information to an online service for analysis. Also described is offline replacement of operating system files that cannot be cleaned or removed when online.

Abstract: Systems, methods and apparatus for automatically identifying a version of a file that is expected to be present on a computer system and for automatically replacing a potentially corrupted copy of the file with a clean (or undamaged) copy of the expected version. Upon identifying a file on the computer system as being potentially corrupted, a clean file agent may perform an analysis based on the identity of the file and one or more other properties of the system to determine the version of the file that is expected to be present on the system. Once the expected version is identified, a clean replacement copy of the file may be obtained from a clean file repository by submitting a version identifier of the expected version. The version identifier may be a hash value, which may additionally be used to verify integrity of the clean copy.

Abstract: The subject disclosure relates to antimalware scanning, and more particularly to offline antimalware scanning of a host environment via an alternate, known safe operating system. An offline scanning product obtains data previously written by the host environment online antimalware scanning tool, e.g., configuration data and antimalware signatures in shared data stores accessible to the offline and online products, and uses that data to perform the offline antimalware scan. The offline scanning product writes results information and any quarantined files to other shared data stores, whereby the online environment, when rebooted, has access to the information, such as for review and to upload telemetry information to an online service for analysis. Also described is offline replacement of operating system files that cannot be cleaned or removed when online.

Abstract: Systems, methods and apparatus for automatically identifying a version of a file that is expected to be present on a computer system and for automatically replacing a potentially corrupted copy of the file with a clean (or undamaged) copy of the expected version. Upon identifying a file on the computer system as being potentially corrupted, a clean file agent may perform an analysis based on the identity of the file and one or more other properties of the system to determine the version of the file that is expected to be present on the system. Once the expected version is identified, a clean replacement copy of the file may be obtained from a clean file repository by submitting a version identifier of the expected version. The version identifier may be a hash value, which may additionally be used to verify integrity of the clean copy.