SERVER DRIFT MONITORING

• US 20160173525A1
• Filed: 12/15/2014
• Published: 06/16/2016
• Est. Priority Date: 12/15/2014
• Status: Active Grant

• Current Assignee: Sophos Limited (Sophos Group Ltd.)
• Original Assignee: Sophos Limited (Sophos Group Ltd.)
• Inventors: Thomas, Andrew J., Ray, Kenneth D., Harris, Mark D.
• Granted Patent: US 9,774,613 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 63/1408 by monitoring network traffic monitoring network traffic per se H04L43/00
• CPC Class Codes: H04L 63/145 the attack involving the propagation of malware through the network, e.g. viruses, trojans or worms
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227

Abstract

Threat detection is improved by monitoring variations in observable events and correlating these variations to malicious activity. The disclosed techniques can be usefully employed with any attribute or other metric that can be instrumented on an endpoint and tracked over time including observable events such as changes to files, data, software configurations, operating systems, and so forth. Correlations may be based on historical data for a particular machine, or a group of machines such as similarly configured endpoints. Similar inferences of malicious activity can be based on the nature of a variation, including specific patterns of variation known to be associated with malware and any other unexpected patterns that deviate from normal behavior. Embodiments described herein use variations in, e.g., server software updates or URL cache hits on an endpoint, but the techniques are more generally applicable to any endpoint attribute that varies in a manner correlated with malicious activity.

Claims

1. A method comprising:

configuring a plurality of servers, each one of the plurality of servers including one or more executables forming a baseline;

instrumenting the plurality of servers to detect a drift including a change in the one or more executables from the baseline of the one of the plurality of servers;

monitoring the drift of the plurality of servers; and

initiating a remedial action when a drift of a first one of the plurality of servers deviates beyond a predetermined threshold from a drift of each other one of the plurality of servers.

2. The method of claim 1 wherein the one or more executables include at least one of a native executable file, an interpreted file, a script, a dynamic linked library, and an Adobe flash file.

3. The method of claim 1 wherein the change includes an update to an application.

4. The method of claim 1 wherein the change includes an installation of a new application.

5. The method of claim 1 wherein the change includes an addition of at least one of a new dynamic linked library, a resource file, interpreted data file, and configuration file.

6. The method of claim 1 wherein the remedial action includes at least one of a quarantine, a deactivation, and a notification.

7. The method of claim 1 wherein monitoring includes filtering at least one change to exclude the at least one change from the drift.

8. The method of claim 7 wherein the filtering includes filtering at least one change initiated by a trusted updater.

9. The method of claim 1 wherein monitoring includes monitoring by a number of classes of changes, wherein the predetermined threshold is a different threshold for each of the number of classes.

10. The method of claim 9 wherein the number of classes specify one or more actors initiating changes selected from a group consisting of an application, a user of the application, a passive authorized user, an active authorized user, and a trusted updater.

11. A computer program product comprising non-transitory computer executable code embodied in a non-transitory computer readable medium that, when executing on one or more computing devices, performs the steps of:

configuring a plurality of servers, each one of the plurality of servers including one or more executables forming a baseline;

instrumenting the plurality of servers to detect a drift including a change in the one or more executables from the baseline of the one of the plurality of servers;

monitoring the drift of the plurality of servers; and

initiating a remedial action when a drift of a first one of the plurality of servers deviates beyond a predetermined threshold from a drift of each other one of the plurality of servers.

12. The computer program product of claim 11 wherein the one or more executables include at least one of a native executable file, an interpreted file, a script, a dynamic linked library, and an Adobe flash file.

13. The computer program product of claim 11 wherein the change includes an update to an application.

14. The computer program product of claim 11 wherein the change includes an installation of a new application.

15. The computer program product of claim 11 wherein the change includes an addition of at least one of a new dynamic linked library, a resource file, interpreted data file, and configuration file.

16. The computer program product of claim 11 wherein monitoring includes filtering at least one change to exclude the at least one change from the drift.

17. The computer program product of claim 16 wherein the filtering includes filtering at least one change initiated by a trusted updater.

18. The computer program product of claim 11 wherein monitoring includes monitoring by a number of classes of changes, wherein the predetermined threshold is a different threshold for each of the number of classes.

19. The computer program product of claim 18 wherein the number of classes specify one or more actors initiating changes selected from a group consisting of an application, a user of the application, a passive authorized user, an active authorized user, and a trusted updater.

20. A system comprising:

a plurality of servers each configured with one or more executables forming a baseline;

a local drift monitor executing on each one of the plurality of servers, the local drift monitor configured to detect a drift including a change in the one or more executables; and

a threat management facility coupled in a communicating relationship with each one of the plurality of servers, the threat management facility including a global drift monitor configured to monitor data from the local drift monitor on each one of the plurality of servers, and the threat management facility configured to initiate a remedial action when a drift of a first one of the plurality of servers deviates beyond a predetermined threshold from a drift of each other one of the plurality of servers.

21. A method comprising:

configuring a plurality of servers;

instrumenting the plurality of servers to detect a behavior;

monitoring the behavior on each of the plurality of servers; and

initiating a remedial action when the behavior on a first one of the plurality of servers deviates beyond a predetermined threshold from the behavior on each other one of the plurality of servers.