Anyone attending this conference knows the usefulness of running malware in a sandbox to perform triage, speed security analysts' workflow, extract indicators of compromise (IOCs), and to gather useful information for detection and mitigation. When analysts do this, what are the OPSEC concerns regarding tipping the adversary off? Which sandbox providers are better than others in this regard? In this talk we will present some research on taking an adversarial view of the free and widely used SaaS malware sandboxes. When an adversary's malware is detonated in a sandbox, what network artifacts can they see? Can they determine which sandbox provider based on the network? How do malware and related IOCs submitted to these sandboxes propagate to security companies and ultimately threat intelligence feeds? In this talk, we will answer all these questions and more.