How to identify a compromised EC2 instance using VPC Flow logs and Amazon GuardDuty

Amazon GuardDuty is a threat detection service that utilizes machine learning and integrates with AWS security services such as Amazon CloudTrail, VPC flow logs, and AWS WAF to identify malicious activities and unauthorized behavior in AWS accounts and workloads. By establishing activity baselines and detecting deviations, GuardDuty can identify threats ranging from malware to unauthorized cryptocurrency mining, providing actionable insights without the need for manual analysis or writing ETL code. The blog outlines how to set up GuardDuty, highlighting the ease of enabling VPC flow logs and configuring the service to detect and respond to security threats. An example scenario demonstrates how GuardDuty can identify a port scanning attack on an EC2 instance, with the findings offering detailed forensic insights and remediation recommendations. The text emphasizes the tool's ability to transform raw data into valuable security intelligence, enhancing security posture with minimal effort, and also discusses the use of Amazon EventBridge for automated notifications of GuardDuty findings.