Hunting reverse shells: How the Sysdig Threat Research Team builds smarter detection rules

The Sysdig Threat Research Team (TRT) focuses on developing effective detection rules to identify reverse shells, a common remote access tool used by attackers to control compromised systems. Reverse shells initiate a connection from the victim's machine to the attacker's system, bypassing firewall restrictions on incoming connections. The TRT analyzes various reverse shell techniques, including direct shell execution with network-redirected input/output, indirect shell execution using interprocess communication, and direct command execution without a traditional shell. By understanding the anatomy of reverse shells and their associated system calls, Sysdig TRT creates rules that balance reducing false positives with broad detection capabilities. They continuously refine these rules to improve accuracy and adapt to evolving threats, ensuring robust protection for Sysdig customers and open source Falco users against the latest adversarial techniques in the cloud landscape. These efforts involve implementing new fields in detection rules and leveraging stateful workload detection policies to enhance the relevance and precision of threat detection.