Investigating S3 Scanning Activities on AWS
During the past week, we detected some suspicious activities across multiple AWS accounts in one of our clients’ environments. These activities seemed related to S3 bucket scanning by a bad actor. Here is one of the sample logs from the S3 access logs: 84fd7086179626a759fb59a0252a26d26dc1685e30f0ab922266b5abace8f998 <AWS-ACCOUNT-ID>-config-org-bucket [01/Jun/2020:13:27:34 +0000] 10.247.13.187 arn:aws:iam::799199334739:user/starling-ladyblackhawk-iad-prod 9WDX6MBZFQ6Z6RDR REST.HEAD.BUCKET - "HEAD / HTTP/1.1" 403 AccessDenied 243 - 9 - "-" "AWSConfig" - wFvPfIaSbdpcnNMdcTj+BNWn00r3OfqHV8sTt8gUXMzLA7O/MiWg+NPckix2TThK15V/p1JigVc= SigV4 ECDHE-RSA-AES128-SHA AuthHeader <AWS-ACCOUNT-ID>-config-org-bucket.s3.amazonaws.com TLSv1.2 The first thing that caught our attention in this log was the username starling-ladyblackhawk-iad-prod....