Global darknet monitoring provides an effective way to observe cyber-attacks that are significantly threatening network security and management. In this paper, we present a study on characterization of cyberattacks in the big stream data collected in a large scale distributed darknet using association rule learning. The experiment shows that association rule learning in the darknet stream data can support strategic cyberattack countermeasure in the following ways. First, statistics computed from malware-specific rules can lead to better understanding of the global trend of cyberattacks in the Internet. Second, strong association rules can lead to further insights into the nature of the attacking tools and hence expedite the diagnosis. Then, the discovery of emerging new attacks may lead to early detection and prompt prevention of pandemic incidents, preventing damage to the IT infrastructure and extensive financial loss. Finally, exploring the knowledge in the frequent attacking patterns can enable accurate prediction of future attacks from analyzed hosts, which could improve the performance of honeypot systems to collect more pertinent malware information using limited system and network resources.