The New Zealand stock exchange (NZX) has been the victim of a Distributed Denial-of-Service (DDoS) attack that has forced it to shut down. Twice over the past 48 hours, NZX has been forced to halt all trading due to these attacks. A DDoS attack, in its simplest terms, is a resource exhaustion attack in which an attacker uses a botnet to flood the network with more traffic than it is designed to handle. While NZX hasn’t named the threat actor or the method used to launch the DDoS attacks, there is a large chance that an attacker used a DDoS-for-hire service. Law enforcement agencies across the globe are actively trying to shut down these services and track down the originators and users of these services. A report from Kaspersky Labs estimates the cost of these attacks to be around $120,000 each for small businesses and over $2 million for large organizations.