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Covert Data Channels. When Insiders Attack. Overview. Introduction Covert Storage Channels Covert Timing Channels Channel Operation Channel Detection Discussion. Ping. Ping. Ping. Ping. Introduction. Altering otherwise normal network traffic to secretly transmit information.
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Covert Data Channels When Insiders Attack
Overview • Introduction • Covert Storage Channels • Covert Timing Channels • Channel Operation • Channel Detection • Discussion Ping Ping Ping Ping
Introduction • Altering otherwise normal network traffic to secretly transmit information
Covert Storage Channels • Data is written to and read from sections of network packets not intended for data transmission. • Altering packet payload data is usually considered subliminal instead of covert. • Use space in protocol headers
Covert Timing Channels • Alter the timing of otherwise legitimate network traffic to transmit data • Two types of timing channels: Active and Passive • IP Covert Timing Channels • Time-Replay Timing Channels • JitterBug
Channel Operation • Efficacy • Contention noise • Jitter • Speed • US Constitution • 7620 words, 45703 characters, 14298 zip • 1 Mbps line, 85 packets per second
Channel Detection • Similarity • Compressibility • Entropy
Discussion • How could IP spoofing be used with covert channels? • What protocols might be useable even on an extremely locked down network?
References [1] Gianvecchio, S. and Wang, H. 2007. Detecting covert timing channels: an entropy-based approach. In Proceedings of the 14th ACM Conference on Computer and Communications Security (Alexandria, Virginia, USA, October 28 - 31, 2007). CCS '07. ACM, New York, NY, pp. 307-316. [2] Cabuk, S., Brodley, C., and Shields, C. 2009. IP Covert Channel Detection. ACM Transactions on Information System Security, Volume 12, Issue 4 (Apr. 2009), pp. 1-29. [3] Thyer, J. 2008. Covert Data Storage Channel Using IP Packet Headers. Global Information Assurance Certification, Gold Certification, SANS Institute, pp. 1-53.