In the last years there has been an increase in the amount of malware using HTTPS traffic for their communications. This situation pose a challenge for the security analysts because the traffic is encrypted and because it mostly looks like normal traffic. Therefore, there is a need to discover new features and methods to detect malware without decrypting the traffic. A detection method that does not need to unencrypt the traffic is cheaper (because no traffic interceptor is needed), faster and private, respecting the original idea of HTTPS. The goal of this thesis is to detect HTTPS malware connections by extracting new features and using data from the Bro IDS program. Since the data for the research is hard to come by, we used data from the Stratosphere project and we created, by hand, our own datasets. Our unit of analysis is an aggregation of all the information that is possible to obtain without decrypting the data. We group together flows, SSL data and X.509 certificates data as they are generated by Bro. To classify the HTTPS malware traffic we used several algorithms, such as Neural Networks, XGBoost and Random Forest. Our results show that the HTTPS malware behaviour is distinct from normal HTTPS behaviour and that our methods are able to separate them with an accuracy of at least 96.64%.