On behalf of the Program Committee, it is our pleasure to present the proceedings of the 8th Symposium on Recent Advances in Intrusion Detection (RAID 2005), which took place in Seattle, Washington, USA, September 7-9, 2005. The symposium brought together leading researchers and practitioners from academia, government and industry to discuss intrusion detection from research as well as commercial prospectives. We also encouraged discussions that addressed issues that arise when studying intrusion detection, including monitoring, performance and validation, from a wider perspective. We had...