Network Asset Discovery & Tracking Vern Paxson University of California Berkeley, California USA August 23, 2010

Overview Grounding asset discovery in reality: empirical enterprise data  Acquired extensive data from operational environments Supporting asset discovery and tracking with capture/archive technology  VAST = Visibility Across Time and Space  Enhancing “time machine” technology towards operational use Exploration of asset discovery algorithms  Mining for unique signatures & clusters

Access To Empirical Enterprise Data Leveraging ties with operational cybersecurity at Lawrence Berkeley National Lab (LBL), we obtained access to extensive raw internal logs  ~4,000 users, ~12,000 internal hosts, Gbps/10Gbps  Archive resides beyond OTP portal  Exportable to team members we work with using negotiated anonymization Can also mediate access via running analyses via portal  Ground truth (or at least partial) available  Topology, historical DNS also available

Scope of the Data Netflow: 74B records across 15 months  Recorded at 3 internal core routers  5-minute dumps  ~1K flows/sec LDAP: 4.5 years, 5.6B records DNS: 5 years, 47B records 5 years, 17B records  Received, sent, read via {POP,IMAP,HTTP} DHCP: 2 months, 144M records Individual systems: 2 months, 1.6B records Logs are a pain to deal with. Written in many distinct formats, meant for human-not- machine consumption

VAST: Motivating Premise Modern serious attacks often manifest –Over a range of time scales –Involving numerous system components Serious = –E.g. stolen credentials –E.g. insiders, spear-phishers Detecting these requires broad visibility –Across time (into the past; looking to the future) –Across space (different forms of sensing; inter- site)

A General Network Time Machine Policy-neutral data Uniform data model VAST Repository For assets: Extensive uniform logging of activity for mining/discovery Unified asset tracking using general data model

VAST DB System Architecture Event Streams DispatcherDispatcher Query Engine OperatorOperator EventDataEventDataIndexIndex Aggr.Aggr. Archive Stream Query Engine Live Analysis

Exploring Longitudinal Patterns of Enterprise Activity Visualization of internal DNS lookups of internal LBL hosts –Based on longitudinal DNS logs X axis: position in LBL address space Y axis: scaled to number of lookups (Demo)

Preliminary Exploration of Netflow Data Single day from LBL –9,702 source hosts, 11,362 destinations Removed internal scanners Very simple clustering: Jaccard index on each host’s destinations –Note: doesn’t mean host was client Initial crunch took ~24 CPU hours –Coded in Scala, 15 minutes on 17-node cluster For exact matches, 91% of hosts unique Remainder exhibit ~ power-law structure

Preliminary Exploration of Connection Patterns To what degree does a host’s past activity suffice to distinguish its future activity? –Use #1: find hosts that significantly alter their behavior E.g., due to failure/failover –Use #2: track assets / disambiguate NAT/DHCP aliasing –Use #3: understand what makes a host unique (~ “role discovery”) / find similar hosts Outbound traffic data set: 402 non-NATed source hosts –1,528,619 distinct destinations –168 days Outbound HTTP data set: 160 non-NATed source hosts –62,031 distinct HTTP host header destinations –137 days

Fingerprinting End Systems, con’t So far, two assessments: –A: train first 10 days, evaluate on next 10 days –B: train first 30 days, evaluate on next 30 days Classification approach #1: Naïve Bayes –Use destinations as symbols for bag-of-words –P[Correct system in scenario A]: 53% –P[Correct system in scenario B]: 53% However: in failure instances, often the correct system is near the top …

Fingerprinting End Systems, con’t Classification approach #2: Jaccard index –Destinations weighted by their relative rarity –P[Correct for A]: 77% –P[Correct for B]: 70%  Benefit in considering constellations of destinations rather than just individual destinations in isolation

Next Steps Begin navigating huge LBL logs to determine –Extent of information available –Efficient & sound ways to sample/slice data –Low-hanging fruit for asset identification Work towards operational VAST deployment to gather future such data in a unified/coherent fashion Refine clustering techniques towards identifying sets of servers, including backups Develop/refine fingerprinting techniques for asset tracking