This book constitutes the refereed proceedings of the 5th International Conference on Detection of Intrusions and Malware, and Vulnerability Assessment, DIMVA 2008, held in Paris, France in July 2008.The 13 revised full papers presented together with one extended abstract were carefully reviewed and selected from 42 submissions. The papers are organized in topical sections on attack prevention, malware detection and prevention, attack techniques and vulnerability assessment, and intrusion detection and activity correlation.