Intrusion Prevention Systems Ahmed Saeed Team Leader (Cisco Division) CTTC (PVT) Limited

What is IPS? Intrusion Prevention System A system located on the network that monitors the network for issues like security threats and policy violations, then takes corrective action. Performs Deep Packet Inspection

What can an IPS do? IPS can detect and block: OS, Web and database attacks Spyware / Malware Instant Messenger Peer to Peer (P2P) Worm propagation Critical outbound data loss (data leakage)

Difference between IDS and IPS Intrusion Detection System (IDS) Passive Hardware\software based Uses attack signatures Configuration SPAN/Mirror Ports Generates alerts (email, pager) After the fact response Intrusion Prevention System (IPS) Inline & active Inline w/fail over features. Real time response

IPS Types IPS can be grouped into 3 categories Signature Based Anomaly Based (NBAD) Hybrid

Signature Based Use pattern matching to detect malicious or otherwise restricted packets on the network Based on current exploits (worm, viruses) Detect malware, spyware and other malicious programs. Bad traffic detection, traffic normalization

Signature Based Products Sourcefire / Snort StillSecure NFR Cisco IOS IPS

Signature: Pro’s & Con’s Very flexible. Well suited to detect single packet attacks like SQL Slammer. Con’s Relatively little Zero Day protection. Generally requires that the attack is known before a signature can be written.

Anomaly Based Anomaly based IPS look for deviations or changes from previously measured behavior like: Substantial increase in outbound SMTP traffic New open ports or services Analyzes TCP/IP Parameters changes

Anomaly Based Products Mazu Networks Arbor Networks Q1 Labs Top Layer

Anomaly: Pro’s & Con’s Pro’s Con’s Better protection against Zero Day threats Better detection of “low and slow” attacks Con’s Cannot protect against single packet attacks like SQL slammer Cannot analyze packets at layers 5 – 7 of the OSI model

Hybrid IPS Hybrid IPS combine Signature Based IPS and Anomaly Based IPS into a single device

Hybrid Products Juniper Cisco IBM-ISS TippingPoint McAfee

Hybrid Pro’s & Con’s Pro’s Con’s Superior protection for both known and Zero Day threats Each plays off the weakness of the other Con’s Generally more expensive than either Anomaly or Signature based products Can be slower depending on architecture

Architecture: Software vs. Hardware Software based Generally runs Linux or a BSD variant EG: Snort / Sourcefire, NitroSecurity, StillSecure Hardware based Uses ASIC / FPGA technology EG: TippingPoint, Top Layer, McAfee

Software Pro’s & Con’s Pro’s Con’s More flexible Generally easier to add major functionality Cheaper Generally has more functionality Con’s Usually slower than hardware Latency is usually higher than hardware

Hardware Pro’s & Con’s Pro’s Con’s Speed, Speed, Speed Lower latency than software Less moving parts to fail Con’s Expensive Not easily upgradeable Major upgrades usually mean new ASIC chips

What about UTM? Unified Threat Manager All-in-one devices that can do: Firewall Antivirus IPS VPN Etc. This is being discussed because vendors very often push UTM devices when customers are looking for IPS solutions

UTM Products Fortinet Radware SonicWall ISS-Proventia Cisco (ASA appliance) Juniper (SSG and ISG Firewalls)

UTM Pro’s & Con’s Pro’s Con’s Cost effective for remote branch offices where other capabilities like Firewall are also needed Con’s Usually a limited subset of IPS functionality and signatures as compared to stand alone IPS products

Thinking about an IPS? Why? What problem are you trying to solve? What other problems may be solved? What problems may arise? If Networking is a different group than Security, do you have their buy in?

Tips when selecting an IPS Prepare an RFP You can get a sample one from Internet Do an on-site POC of your top choices It’s vital to see how the device works in your network. Make sure you test their support, especially if you are going to buy 24x7 Look for products certifications ICSA, NSS Group, Neohapsis

What to consider when buying Speed / latency Will the device perform under load? Is the latency acceptable? Very important if you have VOIP! Accuracy How many attacks did it miss? How many false attacks did it block? Signature Updates Absolutely critical. How often the signatures are updated is a key indicator of how serious they are about selling IPS High Availability Will it do Active-Passive, Active-Active? "Fail Open“ Will the device pass traffic in the event of a device failure?

IPS Testing and Certifications Testing & certifications are done by ICSA Labs NSS Group Neohapsis ICSA is the newest NSS is arguably the most respected, for now. The IPS should have at least one certification

Questions?

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