Network Security

Network Security

Mike Yoho, Jason Letostak,Brian Hixenbaugh, Todd Saylor

Objectives• Know who the attackers are

• Know the kinds of attacks

• Network defenses

• Wireless defenses

• Vulnerability assessment

• Live WEP crack

What is Network Security?

• That which protects the integrity, confidentiality, and availability of information on devices that store, manipulate, and transmit the information through products, people, and procedures.

Characteristics of Data

• Confidentiality– HIPAA, trade secrets, etc.

• Integrity– Medical records, Criminal records, etc.

• Availability– Emergency action procedures, Intelligence

networks, etc.

Who are the Attackers

Types Skill Level Reasons for attack Threat Level

Hackers High Ego, display vulnerabilities

Low

Script Kiddies Low Cause Damage Moderate

Employees Low Retaliation, Carelessness

Moderate

Computer Spies Very High Money High

Cyber Criminals High Money, Fraud High

Cyber Terrorists High Ideology, principles, beliefs

Feared

Categories of Attack• Denial of Service (DoS Attack)– Used to overload target’s network resources

• Spoofing– Impersonate trusted system to gain network access

• Man-in-the-middle– Collect information from network traffic

• Rogue access point– Used to bypass a companies external firewall

• Brute Force– Used to gain access to encrypted data

Network Defences

• Authentication

• Firewalls

• Intrusion Detection\Prevention Systems

• Virtual Private Networks

Authentication

• Remote Authentication Dial-in User Service (RADIUS)

•Strong passwords

Firewalls

• Inspect incoming and outgoing packets

• Block traffic according to rules

• More advances systems can restrict individual applications

Intrusion Detection/Prevention Systems

•Detect and report/block suspicious network traffic activity

•Able to learn normal network traffic patterns

Virtual Private Networks

Wireless Network Security

• Wired Equivalent Protection (WEP)

• Wi-Fi Protected Access (WPA, WPA2)

• Service Set Identifiers (SSID)

Wired Equivalent Protection (WEP)

• Designed to be roughly as secure as a wired connection

• Uses 24 bit initialization vector

• Found to be relatively easy to crack

• Superseded in 2003 by WPA

Wi-Fi Protected Access (WPA, WPA2)

• Created after WEP found vulnerable

• WPA with temporal key integrity protocol (TKIP) release as a stop-gap to replace WEP

• WPA2 completed in 2004– Pre-shared key encryption (PSK)– Support for protected extensible authentication

protocol (PEAP)

Service Set Identifier (SSID)

• Identifier used to differentiate wireless access points

• Can be set to not broadcast adding a low level of security

• Should be changed from the default to help protect from WPA brute force attacks

Vulnerability Assessment• Port Scanning

• Protocol analyzer

• Vulnerability scanner

• Password Cracking

• Penetration Testing

Port Scanning

• Scanner analyzes the ports on a network and determines if they are:– Open: actively listening and accepting connections– Closed: port is not accepting connections– Filtered : no response from the scanned system.

• Tool: nMap(Windows/Linux)

nMAP

Protocol Analyzers

• Also known as Packet Sniffer– Logs network traffic– Analyzes packets– Attempts to decrypt packets

• Tool: WireShark(Windows/Linux)

WireShark

Vulnerability Scanner

• Software designed to:– Map all network devices– Scan network/system– Find Vulnerabilities– Give suggestions on how to make secure

• Doubled Edge Sword• Tool: Nessus

Nessus

Password Cracking

• Software that employs various algorithms in an attempt to discover passwords.

• Keyloggers, Cross-Scripting, Dictionary Tables, Rainbow tables.

• Tool: Hydra (Online), Rainbow Crack (Offline)

Hydra

Rainbow Crack

Penetration Testing

• Method of evaluating the security of a computer system or network by simulating an attack from a malicious source.

• “Ethical Hacker” is hired to perform– Security Audit– Exploit vulnerabilities– Help secure the week points.

• Tool: Back Track 4

Live WEP Crack Demonstration

• Using Ubuntu with Backtrack 4

• Decrypt a 128 bit authentication key

• WEP key: – 43:40:9f:91:d5:33:03:9e:6e:5b:60:dd:6c

Conclusion

“The only truly secure computer, is a dead computer.” –Ransel Yoho III, Network Security Architect

Education of users & administrators – first line of defense Use software to test network vulnerability regularly Although new security methods will be developed,

remember that no network will ever be completely un-hackable