Networked computers are ubiquitous, and are subject to attack, misuse, and abuse. One method to counteracting this cyber threat is to provide security analysts with better tools to discover patterns, detect anomalies, identify correlations, and communicate their findings. Visualization for computer security (VizSec) researchers and developers are doing just that. VizSec is about putting robust information visualization tools into the hands of human analysts to take advantage of the power of the human perceptual and cognitive processes in solving computer security problems. This volume collects the papers presented at the 4th International Workshop on Computer Security - VizSec 2007.

Networked computers are ubiquitous, and are subject to attack, misuse, and abuse. One method to counteracting this cyber threat is to provide security analysts with better tools to discover patterns, detect anomalies, identify correlations, and communicate their findings. Visualization for computer security (VizSec) researchers and developers are doing just that. VizSec is about putting robust information visualization tools into the hands of human analysts to take advantage of the power of the human perceptual and cognitive processes in solving computer security problems. This volume collects the papers presented at the 4th International Workshop on Computer Security - VizSec 2007.

This volumecontains the paperspresented at VizSec 2008, the 5th International Workshop on Visualization for Cyber Security, held on September 15, 2008 in Cambridge, Massachusetts, USA. VizSec 2008 was held in conjunction with the 11thInternationalSymposiumonRecentAdvancesinIntrusionDetection(RAID). There were 27 submissions to the long and short paper categories. Each submission was reviewed by at least 2 reviewers and, on average, 2.9 program committee members. The program committee decided to accept 18 papers. The program also included an invited talk and a panel. The keynote address was given by Ben Shneiderman, University of Maryland at College Park, on the topic InformationForensics: HarnessingVisualizationto SupportDiscovery.The panel, on the topic The Need for Applied Visualization in Information Security Today, wasorganizedandmoderatedbyTobyKohlenbergfromIntelCorporation. July 2008 John R. Goodall Conference Organization Program Chairs John R. Goodall Secure Decisions division of Applied Visions Gregory Conti United States Military Academy Kwan-Liu Ma University of California at Davis Program Committee Stefan Axelsson Blekinge Institute of Technology Richard Bejtlich General Electric Kris Cook Paci?c Northwest National Laboratory David Ebert Purdue University Robert Erbacher Utah State University Deborah Frincke Paci?c Northwest National Laboratory Carrie Gates CA Labs John Gerth Stanford University Barry Irwin Rhodes University Daniel Keim University of Konstanz Toby Kohlenberg Intel Corporation Stuart Kurkowski Air Force Institute of Technology Kiran Lakkaraju University of Illinois at Urbana-Champaign Ra?ael Marty Splunk Douglas Maughan Department of Homeland Security John McHugh Dalhousie University Penny Rheingans UMBC Lawrence Rosenblum National Science Foundation George Tadda Air Force Research Lab Daniel Tesone Applied Visions Alfonso Valdes SRI Internatio