Maciej Pocwierz, a senior software engineer Semantive, writing on Medium: A few weeks ago, I began working on the PoC of a document indexing system for my client. I created a single S3 bucket in the eu-west-1 region and uploaded some files there for testing. Two days later, I checked my AWS billing page, primarily to make sure that what I was doing was well within the free-tier limits. Apparently, it wasn’t. My bill was over $1,300, with the billing console showing nearly 100,000,000 S3 PUT requests executed within just one day! By default, AWS doesn’t log requests executed against your S3 buckets. However, such logs can be enabled using AWS CloudTrail or S3 Server Access Logging. After enabling CloudTrail logs, I immediately observed thousands of write requests originating from multiple accounts or entirely outside of AWS.
Was it some kind of DDoS-like attack against my account? Against AWS? As