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IPv6 and Spam 2009 MIT Spam Conference

IPv6 and Spam 2009 MIT Spam Conference. Peter Kosik, Patrik Ostrihon and Reza Rajabiun reza@comdomsoft.com. Spam Economics. End user and network costs of spam ITU (2008): Economic implications of malware and spam (bandwidth, processing, storage, annoyance, etc.)

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IPv6 and Spam 2009 MIT Spam Conference

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  1. IPv6 and Spam2009 MIT Spam Conference Peter Kosik, Patrik Ostrihon and Reza Rajabiunreza@comdomsoft.com © ComDom Software | www.comdomsoft.com | info@comdomsoft.com

  2. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Spam Economics • End user and network costs of spam • ITU (2008): Economic implications of malware and spam (bandwidth, processing, storage, annoyance, etc.) • This paper: A more pernicious problem • Spam also limits incentives to adopt efficiency enhancing technologies and standards • Specifically: Constrains the diffusion of IPv6 at the AS level • Implications: Technological sclerosis and network fragmentation • Why? Alters the relative capacities of attackers/defenders

  3. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Relevance(Source: Amsterdam Internet Exchange)

  4. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com IPv6 Economics • Demand: • Address space exhaustion (128 v. 32 bit design) • Network Address Translation leads to fragmentation (big problem in developing countries in particular) • Supply: • Very limited even in countries with more to gain from a switch • Less than 1% in all countries (Google, 2008), • Leaders in deploying IPv6: • Entities with need for large space: DOD, cable operators (IPv6 lite)

  5. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Allocation of address space(Source: CAIDA)

  6. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Emerging IPv6 network(Source: Dolphin Network Discovery System, Key State Laboratory)

  7. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com IPv6 Diffusion • Not an end user problem: • End users usually do not make choices about IP • Technology bundling: Transition between Windows XP to Vista required to stimulate ISP investment in IPv6 specific infrastructure. • Vista necessary, but not sufficient for IPv6 diffusion • Why? Positive network externalities: Multiple equilibrium problem in the level of diffusion • Central variable: Decisions by Autonomous Systems/upstream operators

  8. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Technological decisions • Traditional diffusion model • S-curve: A small proportion of population adopt first, then rate increases --> Deterministic • Elmore et al. (2008): Significant resistance to IPv6 adoption. • Possible solutions: • Public subsidies • Partial mandates • Technological bundling

  9. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Technological decisions • AS decision interdependence • Game theoretical perspective --> Stochastic process • In the presence of positive network externalities/strategic complementarities: • Decisions by sellers/firms reinforce each other • Possibility of a stable (inefficient) Nash equilibrium with persistent low penetration • Possibility of rapid shifts from sub-optimal Nash to Pareto efficient states

  10. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Decision processes • AS IPv6 decisions • 1) Delay/not delay investment • 2) Full /IPv6 lite • General model of diffusion of binary decisions in network games. Jackson and Yariv (2007): • In the presence of strategic complementarities, Bayesian Nash equilibrium exists and conveyance behavior monotone (up/down) • Let x – Prob. of random network i adopting IPv6 • Let d – Degree distribution for network i (links)

  11. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Diffusion • Edge rewiring and stability of equilibrium

  12. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Adopt only if ci ≤ v(di , x) • Three basic decision processes: • When an AS only cares about the average play of her neighbors, and network structure does not matter: v (d,x) = u(x) • When a network’s individual payoff to IPv6 is a function of expected number of neighbors adopting IPv6: v (d,x) = u(dx) • When v(d,x) is a step function, so that the decision to adopt IPv6 takes place only if x lies above a specific subjective threshold.

  13. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Interpretation • If degree distribution matters: • Hypothesis: Decisions by networks with the largest number of linkages will determine the equilibrium level of diffusion. • Xiao et al. (2009): Empirical analysis of emerging topology • Degree distribution of IPv6 ASs follows power law distribution • Power law exponent is around 1.2 (much lower than Ipv4, at approx. 2.2) • IPv6 connectivity less uniformly distributed --> Big networks have to move first

  14. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com IPv6 and Complexity (Source: Dolphin NDS)

  15. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Spam and Technological Decisions • Kimakova and Rajabiun (2008) War of attrition: More spam with more antispam (another example of strategic complementarities) • Kanich et al. (2008): Very low conversion rates (in both responses to mass advertisements and infections) • O'Donnell (2008): Strong incentives to switch to new channels for extracting value from targets (OS vulnerabilities, other messaging applications) • Key question: How does IPv6 change relative capacities of attackers and defenders?

  16. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com IPv6 angles of attack • Three specific channels: • OS/application specific vulnerabilities • usually patched quickly by vendors (See: US-CERT database) • Large address space makes it easier to hide • Erosion of value of sender information • Accuracy: BGP Spectrum Agility techniques and one shot mailings • False positives: Reputation hijacking • Auto configuration and neighbor discovery

  17. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com IPv6 and Spam • IP evolution: • Davis et al. (2006): IPv6 may help with the spam problem, if: • 1) A property regime could be created to make reputation of senders more credible • Would lead to more reputation hijacking and not realistic • 2) The near infinite address space made it more difficult for spammers to probe the network for vulnerabilities

  18. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Downstream admin. • Passive Decisions • MS Exchange 2007 Antispam and Antivirus Functionality: • “…strongly recommend against configuring Receive connectors to accept anonymous connections from unknown IPv6 addresses. If your organization must receive mail from senders who use IPv6 addresses, create a dedicated Receive connector that restricts the remote IP addresses to the specific IPv6 addresses that those senders use. If you configure a Receive connector to accept anonymous connections from unknown IPv6 addresses, the amount of spam that enters your organization is likely to increase.”

  19. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com (Semi) Autonomous Systems • Active Decisions • ISPs with large d's: their IPv6 decisions matter most to diffusion • Problem: • Reliant on DNSRBLs and reputation based filtering (50-60% of the spam/total load) • If IPv6 large address space erodes reputation, then • 1) Forgone investments in spam defenses • 2) Increases in infrastructure costs since reputation is perceived to be cheaper than content analysis (processing, storage, etc.)

  20. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Rational expectations and transition to IPv6 • Port scanning and information gathering: • Bellovin et al. (2006): Using a two stage search process IPv6 neighborhood discovery logs can be used to collect necessary info. • In addition to active scanning techniques, ASs expect that in an IPv6 world: • Target discovery and worm propagation: • Relatively easy since computers in IPv6 space will likely live near each other (given adjacent addresses by ISPs). Much like agglomeration of people in cities.

  21. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Spamming in IPv6 • Shifting targeting paradigm • Most computers in the world already protected by NATs from active and passive scanning • Result: • Spammers devise techniques that let their prey come to them! • Place malicious code on WWW servers. • Infiltrate routers of big ISPs. • Use BGP to redirect traffic.

  22. © ComDom Software | www.comdomsoft.com | info@comdomsoft.com Implications and Discussion • IPv6 lite implementation will not help address the strategic decisions that influence aggregate diffusion rates (edges using NATs and IPv4) • IPv6 diffusion requires complementary changes in technologies for spam processing • Stronger sender authentication (DKIM, etc.), or Accountable Internet Protocol (AIP) as in Andersen et al. (2008). • Increased emphasis on content analysis and statistical filters.

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