As the volume of cyberattacks grows, security analysts have become overwhelmed. To address this issue, developers are showing more interest in using Machine Learning (ML) to automate threat-hunting. In fact, researchers have tried to implement ML in cybersecurity solutions since the late 1980s, but progress has been slow. Today, ML is showing increasing promise with the advent of Big Data because the quality of information from which ML can learn is improving. However, there is much more to be done.