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Making Boring Logs Interesting

In the last week alone, two investigations I have been involved with have come to a standstill due to the lack of attribution logging data. One investigation was halted due to the lack of user activity logging within an application, the other from a lack of network-based activity logs. Convincing the asset owners of the need for logging after-the-fact was easy. But ideally, this type of data would be collected before it’s needed for an investigation. Understanding what data is critical to log, engaging with the asset owners to ensure logs contain meaningful information, and preparing log data for consumption by a security monitoring organization are ultimately responsibilities of the security monitoring organization itself. Perhaps in a utopian world, asset owners will engage an InfoSec team proactively and say, “I have a new host/app. To where should I send my log data which contains attributable information for user behavior which will be useful to you for security monitoring?” In lieu of that idealism, what follows is a primer on logs as they relate to attribution in the context of security event monitoring. Read More »

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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

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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Cisco Hosting Amsterdam 2013 FIRST Technical Colloquium

There is still time to register for the upcoming FIRST Technical Colloquium April 2-3 2013. The event has a very exciting program covering, bitsquatting, webthreats, RPZ, Passive DNS, Real-world monitoring examples, Spamhaus, SIE, Cuckoo Sandbox, Malware Analysis and many more current issues facing the incident response community.

The event’s line-up includes notables from Cisco Security Intelligence Operations (SIO), Internet Systems Consortium, Shadowserver foundation, KPN-CERT, NATO, MyCert and ING amongst others. Program details can be found here.
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Tracking Malicious Activity with Passive DNS Query Monitoring

Ask anyone in the information security field they will tell you:

Security is not fair. There is essentially an unlimited supply of attackers that can test your defenses with impunity until they eventually succeed.

As a member of the Cisco Computer Security Incident Response Team (CSIRT) I’ve seen this asymmetry up close, so I can tell you that good security is really hard. Besides the normal security practices like deploying firewalls, IDS sensors, antivirus (AV), and Web Security Appliances, CSIRT is increasingly looking to the network as a data source. We have been collecting NetFlow for years but we have always wanted additional context for the flow data. While it is true that the Internet is built on TCP/IP, Internet services—both good and bad—are found by name using the Domain Name System (DNS). For years infosec has been network-address-centric and the attackers have adapted. Today it is very common to see malware command and control (C&C) use domain generation algorithms (DGAs), Peer-to-Peer (P2P), or even fast-flux DNS to evade IP address-based detection and blocking. It has become absolutely clear that to keep up with the latest attacks and attackers you must have a view into the DNS activity on your network.

CSIRT has been struggling with limited DNS information for a while now, so I am pleased to say we finally have comprehensive visibility into the DNS activity on our network. Before I dive into how we tackled this problem I should back up and explain a bit more about DNS…

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CSIRT Monitoring for Cisco House at the London 2012 Olympic Games

As part of CSIRT’s mobile monitoring offering for special events, we undertook monitoring of the corporate and customer traffic of the Cisco House at the London 2012 Olympics. This engagement presents us with an excellent opportunity to showcase Cisco technology, while keeping a close watch on potential network security threats. CSIRT monitoring for this event will be active for the entire life-span of the Cisco House, from two months before the Olympics, until two months after.

For the London 2012 engagement, we shipped our gear in a 14RU military-grade rack that is containerized: made for shipping. Inside the mobile monitoring rack we have an assortment of Cisco kit and third-party kit that mirrors the monitoring we do internally:

  • Catalyst 3750 to fan out traffic to all the other devices
  • FireEye for advanced malware detection
  • Two Cisco IronPort WSA devices for web traffic filtering based on reputation
  • Cisco UCS box where we run multiple VMs
  • Lancope StealthWatch collector for NetFlow data
  • and a Cisco 4255 IDS for intrusion detection

We mirror the signatures that we have deployed internally at Cisco out to these remote locations. Depending on the environment where the mobile monitoring rack is deployed, we may also do some custom tuning. The kit in the mobile monitoring rack can do intrusion detection, advanced malware detection, and collect and parse NetFlow and log data for investigation purposes. The Cisco UCS rack server also helps us have several VMs,  allowing us to run multiple tools that complement the other devices in the rack. For example, we run a Splunk instance on a VM to collect the logs generated by all the services. The data from the gear in the mobile monitoring rack is analyzed by our team of analysts and investigators, to eliminate false positives, conduct mitigation and remediation, and finally produce an incident report if required.

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