Introduction The number, type and sophistication of cyber security threats to Australia and Australians are increasing. Due to the varied nature of motivations for cyber adversaries targeting Australian organisations, organisations could be a target for malicious activities even if they do not think the information held on their networks is valuable, or that their business would be of interest to cyber adversaries. This first unclassified report by the ACSC describes the range of cyber adversaries targeting Australian networks, explains their motivations, the malicious activities they are conducting and their impact, and provides specific examples of activity targeting Australian networks during 2014. This report also offers mitigation advice on how organisations can defend against these activities. The ACSC’s ability to detect and defend against sophisticated cyber threats continues to improve. But cyber adversaries are constantly improving their tradecraft in their attempts to defeat our network defences and exploit the new technologies we embrace. There are gaps in our understanding of the extent and nature of malicious activity, particularly against the business sector. The ACSC is reaching out to industry to build partnerships to improve our collective understanding. Future iterations of the Threat Report will benefit from these partnerships and help to close gaps in our knowledge.