Malware Traffic Analysis Knowledge Dataset 2019 (MTA-KDD'19) is an updated and refined dataset specifically tailored to train and evaluate machine learning based malware traffic analysis algorithms. To generate it, that authors started from the largest databases of network traffic captures available online, deriving a dataset with a set of widely-applicable features and then cleaning and preprocessing it to remove noise, handle missing data and keep its size as small as possible. The resulting dataset is not biased by any specific application (although specifically addressed to machine learning algorithms), and the entire process can run automatically to keep it updated.