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Traffic Analysis and Risk Assessment of a Medium-Sized ISP. Alan W. Rateliff, II Florida Internet Service Provider Approximately 2000 ADSL users Connections between 256kb/s and 5Mb/s Traffic monitoring between ADSL aggregation device and Internet. The Tool.
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Traffic Analysis and RiskAssessment of a Medium-Sized ISP Alan W. Rateliff, II • Florida Internet Service Provider • Approximately 2000 ADSL users • Connections between 256kb/s and 5Mb/s • Traffic monitoring between ADSL aggregation device and Internet
The Tool • Selected ISP customer DSL traffic is sent to Q-Radar using a network switch “monitor” port • Analyzes captures to identify potentially malicious traffic • Three primary activities used as presentation basis www.q1labs.com
Traffic Anomolies • Protocol and port mismatch500kb/s bursts • Remote system port scanning1.2Mb/s bursts • Internet Relay Chat bot-net controls> 59,000 events over 12-day period • Honorable Mentions • “Direct-to-MX” SMTP transactions (spam, etc.) • P2P Networking (BitTorrent, eDonkey, etc.)
Protocol/Port Mismatches • Protocol communication on a non-common port • Evades port-blocking and monitoring • Firewalls and ACLs • Simple IDS • IANA maintains official list of commonly used or well-known ports • Examples of legitimate port mismatches: • SMTP (port 25) on port 587 • HTTP (port 80) on port 8080
Remote System Port Scans • First stages of attack on a remote system • Probes for services actively accepting connections • Services are probed for known vulnerabilities • Can detect services on non-standard ports • Can identify operating systems • F/OSS Scanner: nmap (insecure.org)
Internet Relay Chat (IRC) Connections • Internet-based “chat rooms” called “channels” • Bot-net clients connect and idle in protected channels • Bot Master issues commands to clients via protected channel • Standard IRC port is 6667(Defined by RFC 1459 and 2812) • Can make use of port mismatching
Con Potential information leaks Potentially subject to disclosure Information could be abused Other privacy concerns Mitigating Violations Pro • Increases end-user security and satisfaction • Decreases network loads • Increases network usability
Discussion • Strict policy and legal controls and enforcement can mitigate privacy concerns • Other pros and cons • Questions and comments