Welcome to the proceedings of the 18th International Symposium on Research in Attacks, Intrusions and Defenses (RAID). Over the past 18 years, RAID has established itself as a highly influential venue with a prime focus on attacks and defenses. We believe that this year was no different, and that the conference once again offered a great program in this increasingly important field of research. We had a large number of submissions, with 119 papers that met the anonymity and formatting guidelines, considerably more than in previous years. Interestingly, authors from European-, US-, and Asian-based institutions each accounted for about one third of the submissions. In terms of the accepted papers, the balance shifted slightly in favor of EU- and US-based authors, but not by much. The Program Committee (PC) selected 28 papers, representing an acceptance rate of 23.5 %. The papers were reviewed using a double-blind reviewing process, ensuring that the reviewers were unaware of the authors or their affiliations until after the selection was finalized. All papers that were on-topic and met the formatting requirements received at least three reviews and the final selection was made during an in-person meeting in Washington DC in August. We thank the authors of both accepted and rejected papers for submitting their papers to RAID. As always, the bulk of the meeting was spent discussing papers where the reviews from the PC were not in agreement. The task at hand was not only to identify those papers that were ready for publication, but to also identify promising work that could be improved before the camera-ready deadline. Out of the 28 selected papers, several were assigned shepherds to ensure that the camera-ready version addressed all the reviewers' concerns and suggested improvements. In many cases, these papers received several rounds of additional feedback by their shepherds. In selecting PC members, we strived to introduce new talent to the RAID conference. Similar to the year before, our goal was to form a PC that included researchers who had not served on the RAID PC more than once in the past few years, and also had a proven track record in terms of top-tier publications. We also made a deliberate attempt to introduce a number of younger researchers, while balancing that with more senior members in the field. Our hope was that in doing so, the younger researchers would gain invaluable experience by serving on the PC, and could help shape the direction of future RAID conferences. It goes without saying that we are indebted to the RAID 2015 PC for selflessly dedicating their time to the process of selecting papers and providing detailed feedback to authors. Serving as a PC member is a hard task, and we believe the recognition for these efforts is often overlooked. For this reason, and to encourage PC members to write critical, yet constructive, reviews, we decided to award an "Outstanding Reviewer" prize to Manos Antonakakis (Georgia Tech) and Konrad Rieck (University of Göttingen). The procedure was that we encouraged PC members to rate each other's reviews. While many reviewers received positive ratings, Konrad and Manos edged out all others with their thoughtful and very helpful reviews and we congratulate them with their well-deserved awards! There are so many other people we need to thank. First, we would like to thank the general chair, Youki Kadobayashi, and his team for the wonderful organization. Until one has been closely involved with a conference, it is hard to appreciate everything that the local arrangements chair has to do, and this conference was no exception. We are very grateful to Kazuya Okada for the job well done. A massive thanks is also owed to Gregory Blanc for handling the publications and making sure that every paper conformed to the format required by Springer, and to Giorgos Vasiliadis for being such a good publicity chair that we had even more submissions than last year. In addition to RAID's main conference, we had a very interesting poster session organized by Sanjay Rawat. The poster session included posters from many of the accepted papers as well as posters that were selected by the poster chair. Finally, we thank the very active and helpful Steering Committee. We hope that you enjoyed RAID conference as much as we enjoyed putting the event together. A great set of papers, covering a wide range of topics, this is what makes RAID truly special. Finally, none of this would be possible without the generous support by our sponsors: Deloitte Tohmatsu Risk Services, Farsight, TAPAD, NTT Communications and Asterisk Research. We are also grateful to Tateishi Science and Technology Foundation for their generous support. We greatly appreciate their help and their continued commitment to a healthy research community in security