Amazon GuardDuty expands threat detection coverage to help you better protect your data stored in Amazon S3

Amazon GuardDuty broadens threat detection coverage to monitor for highly-suspicious data access and anomaly detection to help you better protect your data residing in Amazon Simple Storage Service (Amazon S3). This new capability adds S3 data events (LISTs/PUTs/GETs) as a new log and event source that GuardDuty continuously profiles to monitor data access behavior, combine it with GuardDuty threat intelligence, and identify suspicious activity such as data access from an unusual geo-location, API calls from a known malicious IP address, or unusual API calls consistent with malicious data discovery attempts.

Source:: Amazon AWS