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Big Security—Mining Mountains of Log Data to Find Bad Stuff

Your network, servers, and a horde of laptops have been hacked. You might suspect it, or you might think it’s not possible, but it’s happened already. What’s your next move?

The dilemma of the “next move” is that you can only discover an attack either as it’s happening, or after it’s already happened. In most cases, it’s the latter, which justifies the need for a computer security incident response team (CSIRT). Brandon Enright, Matthew Valites, myself, and many other security professionals constitute Cisco’s CSIRT. We’re the team that gets called in to investigate security incidents for Cisco. We help architect monitoring solutions and strategies and enable the rest of our team to discover security incidents as soon as possible. We are responsible for monitoring the network and responding to incidents discovered both internally by our systems or reported to us externally via csirt-notify@cisco.com.

Securing and monitoring a giant multinational high-speed network can be quite a challenge. Volume and diversity, not complexity, are our primary enemies when it comes to incident response. We index close to a terabyte of log data per day across Cisco, along with processing billions of NetFlow records, millions of intrusion detection alarms, and millions of host security log records. This doesn’t even include the much larger data store of authentication and authorization data for thousands of people. Naturally, like all large corporations, dedicated attackers, hacking collectives, hacktivists, and typical malware/crimeware affect Cisco. Combine these threats with internally sourced security issues, and we’ve got plenty of work cut out for us.

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Security Logging in an Enterprise, Part 2 of 2

This is the second and final part of my series about security logging in an enterprise.

We first logged IDS, some syslog from some UNIX hosts, and firewall logs (circa 1999). We went from there to dropping firewall logging as it introduced some overhead and we didn’t have any really good uses for it. (We still don’t.) Where did we go next? Read on.

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Security Logging in an Enterprise, Part 1 of 2

Logging is probably both one of the most useful and least used of all security forensic capabilities. In large enterprises many security teams rely on their IT counterparts to do the logging and then turn to the IT logging infra when they need log information. That in itself isn’t bad; however, the needs/requirements for IT may not be a 100% fit for a CIRT. Read on to find out how we handled it.

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