Cyberspace plays a dominant role in the world of electronic communication. It is a virtual space where the interconnecting network has an independent technology infrastructure. The internet is the baseline for the cyberspace which can be openly accessible. Cyber-security is a set of techniques used to protect network integrity and data from vulnerability. The protection mechanism involves the identification of threats and taking precaution by predicting the vulnerabilities in the environment. The main cause of security violation will be threats, that are caused by the intruder who attacks the network or any electronic devices with the intention to cause damage in the communication network. These threats must be taken into consideration for the mitigation process to improve the system efficiency and performance. Machine learning helps to increase the accuracy level in the detection of threats and their mitigation process in an efficient way. This chapter describes the way in which threats can be detected and mitigated in cyberspace with certain strategies using machine learning.