INTRUSION DETECTION SYSTEM (IDS) D souza Adam Jerry Joseph I MCA

Transcription

1 INTRUSION DETECTION SYSTEM (IDS) D souza Adam Jerry Joseph I MCA

2 OVERVIEW Introduction Overview The IDS Puzzle Current State of IDS Threats I have a good firewall, why do I need an IDS? Expectations Type of IDS Analyzing Patterns Choosing an IDS Products available on market Ongoing Effort Conclusion / Summary

3 DEFINITIONS: What is Intrusion?... What is Intrusion Detection?... What is Intrusion Detection System?...

4 THE PUZZLE Intrusion Detection Systems are only one piece of the whole security puzzle IDS must be supplemented by other security and protection mechanisms They are a very important part of your security architecture but does not solve all your problems Within its limitations, it is useful as one portion of a defensive posture, but should not be relied upon as a sole means of protection Part of Defense in depth

5 CURRENT STATE OF IDS Lots of people are still using Firewall and Router logs for Intrusion Detection IDS are not very mature Mostly signature based It is a quickly evolving domain Giant leap and progress every quarter The current state of intrusion detection systems relies on careful assessment of vendor proposals and requires a trained systems and network administrator to run the IDS.

7 THREATS FACT OR FICTION?? Frequency vs Difficulty level I am not a target (Yeah, right!) Examples of TOOLS Hacktivists or cyber terrorists The BIGGEST threat

8 FREQUENCY VS DIFFICULTY LEVEL The frequency of probes, attacks, or intrusions attempts is proportional to the difficulty level required to perform such attacks. It is no longer necessary to have any computer knowledge to break through defense mechanisms that are not properly maintained. Many early attackers simply wanted to prove that they could break into systems As e-commerce sites become attractive targets and the emphasis turns from break-ins to denials of service, the situation will likely worsen.

9 WHO ARE THE TARGETS?? Simply being connected is a good enough reason to be a target. Fast bandwidth is now a cheap commodity. No specific motive: They do it for fame, fun, to show off, or just because they have nothing else to do. No technical knowledge is required to be a Script Kiddie

10 E-COMMERCE + WELL KNOWN NAME = HACKER TARGET A clear example is the Denial of service attacks against Yahoo, Ebay, and other popular sites. ISCA Info Security Magazine Sept 2000 Comparison E-Comm site (left column) vs Non E-Comm site (right column) Viruses/Trojan/worm 82% 76% Denial of service 42% 31% Active Scripting exploit 40% 34% Protocol Weaknesses 29% 23% Insecure Passwords30% 20% Buffer Overflow 29% 20% Bugs in web server 33% 16%

11 HACKING TOOLS (EASY TO GET, EASY TO USE, VERY POWERFULL)

12 MY FRIEND SAM SPADE

13 HACKTIVISTS OR CYBER TERRORISTS Very Likely Denial of services attack Computer worms and viruses Likely Breaking into government computer and stealing military secrets or encryption technology Power grid disruption Emergency system being compromised Other internet connected services disruption

14 DIGGING A TUNNEL You spend great money on concrete walls (firewalls) but they are of no use of someone can dig through them.

15 THE BIGGEST THREAT: EXPOSURE The biggest threat of all is bad publicity and having your company reputation and name associated with an intrusion, site modification and defacement, or even attack to other sites using your ressources as a launch platform. It could kill all faith in the belief that you can offer a secure environment to conduct E-Commerce or other online activities. Even thou perception is often not the reality. Outsider and customers does not care that the specific site was on a bronze plan or that it was not hosted in house. PEOPLE ONLY READ LARGE TITLES such as: XYZ GOT HACKED!!!

17 WHY DO I NEED AN IDS, I HAVE A FIREWALL? IDS are a dedicated assistant used to monitor the rest of the security infrastructure Today s security infrastructure are becoming extremely complex, it includes firewalls, identification and authentication systems, access control product, virtual private networks, encryption products, virus scanners, and more. All of these tools performs functions essential to system security. Given their role they are also prime target and being managed by humans, as such they are prone to errors. Failure of one of the above component of your security infrastructure jeopardized the system they are supposed to protect

18 WHY DO I NEED AN IDS, I HAVE A FIREWALL? Not all traffic may go through a firewall i:e modem on a user computer Not all threats originates from outside. As networks uses more and more encryption, attackers will aim at the location where it is often stored unencrypted (Internal network) Firewall does not protect appropriately against application level weakenesses and attacks Firewalls are subject to attacks themselves Protect against misconfiguration or fault in other security mechanisms

19 REAL LIFE ANALOGY It's like security at the airport... You have to let them get to the planes (your application) via the gate ( port 80) but without X- rays and metal detectors, you can't be sure what they have under their coats. Firewalls are really good access control points, but they aren't really good for or designed to prevent intrusions. That's why most security professionals back their firewalls up with IDS, either behind the firewall or at the host.

21 WHAT CAN IDS REALISTICLY DO Monitor and analyse user and system activities Auditing of system and configuration vulnerabilities Asses integrity of critical system and data files Recognition of pattern reflecting known attacks Statistical analysis for abnormal activities Data trail, tracing activities from point of entry up to the point of exit Installation of decoy servers (honey pots) Installation of vendor patches (some IDS)

22 WHAT IDS CANNOT DO Compensate for weak authentication and identification mechanisms Investigate attacks without human intervention Guess the content of your organization security policy Compensate for integrity or confidentiality of information Analyze all traffic on a very high speed network Deal adequately with modern network hardware

24 TYPE OF IDS MONITORING Host Based (also called Agent) -These systems collect and analyze data that originate on a computer that hosts a service, such as a Web server Network Based (also called Sensor) -Network-based intrusion detection analyzes data packets that travel over the actual network. These packets are examined and sometimes compared with empirical data to verify their nature: malicious or benign.

26 TYPE OF ANALYSIS Signature based (Pattern matching) Statistical Integrity Checker

27 HOST BASED (ADVANTAGES) Monitor in term of who accessed what Can map problem activities to a specific user id System can track behavior changes Can operate in encrypted environment Operates in switched networks Monitoring load distributed against multiple hosts and not on a single host, reporting only relevant data to central console

28 HOST BASED (DISAVANTAGES) Cannot see all network activities Running audit mechanisms adds overload to system, performance may be an issue Audit trails can take lots of storage OS vulnerabilities can undermine the effectiveness of agents Agents are OS specific Escalation of false positive Greater deployment and maintenance cost

29 NETWORK BASED (ADVANTAGES) Can get information quickly without any reconfiguration of computers or need to redirect logging mechanisms Does not affect network or data sources Monitor and detects in real time networks attacks or misuses Does not create system overhead

30 NETWORK BASED (DISAVANTAGES) Cannot scan protocols if the data is encrypted Can infer from network traffic what is happening on host but cannot tell the outcome Hard to implement on fully switched networks Has difficulties sustaining network with a very large bandwidth

32 FEATURES TO LOOK FOR Number of rules Which one apply to your specific environment Ability to read whole packet Ability to drill down Deal adequately with fragmentation Updates (how they are done and how often) Reporting features (import, export, flexibility) Support Issues (OS, Platform) Ease of use (What manning is needed)

33 FEATURES TO LOOK FOR What specialized equipment is required Is the product Network or Host based How much does the update cost Is it capable of automated response to attacks How customizable is it What is the incidence rate of false positive What kind of expertise is required to support it

35 LEADING PRODUCTS Dragon from Enterasys CISCO Secure IDS Snort ISS Real Secure SHADOW ftp://ftp.whitehats.ca/pub/ids/shadow-slack/shadow.iso

37 ONGOING SUPPORT There is a need for a COMPETENT analyst Vendors latest signatures may take up to a week after a new threat has be publicized. You will need someone in house that can analyse new vulnerabilities or attacks in order to create your own rule. May take an hour a day or more. Need someone that can fine tune the IDS in order to avoid false positive or false negative Must subscribe to popular advisories and security newsletters such as bugtraq, CERT, GIAC, SANS, and others

39 IDS GOOD GUYS A few initiative is on the way to improve the early detection, accuracy and terminology amongst vendors of ID equipment and software Incident.org, ARIS, MyNetWatchMan CVE ( IDMEF, Intrusion Detection Exchange Message Format - CIDF, Common Intrusion Detection Framework

40 CLOSING An IDS is like a three year old kid, it s not happy unless you are constantly watching it all the time. Contrary to all other devices, An IDS talks back to you and demand immediate attention. One of the most important point is how you are going to monitor your systems, what are you going to do when the alarm goes off at three in the morning? There is about 400 different IDS on the market. Only a few of these products integrate well in large environment, are scalable, and easy to maintain. Acquire the IDS that meets your need, not the one that the vendor think you need.