One-Way C2 Data Posted to Cloud Storage

Darshan Thummar@Mighty

•updated Jun 12, 2026•0•0•3

This rule detects HTTP PUT requests to Amazon S3 or Azure Blob Storage (cloud storage services) where the request body size is between 100 and 2000 bytes. This pattern is often indicative of one-way command and control (C2) communication, where an attacker might be exfiltrating small chunks of data or sending commands to a compromised host via cloud storage. The thresholding mechanism (20 events within 300 seconds from the same source) aims to reduce alerts from legitimate, infrequent cloud storage interactions.