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Topics in network security


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VPN, Malware Analysis, Digital Forensics, Penetration Testing, Firewalls etc.

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Topics in network security

  1. 1. Dr. M Nasir Mumtaz Bhutta Institute of Computing Bahauddin Zakariya University Multan, Punjab, 60,000 Pakistan Email: Network Security Course Miscellaneous Topics 12 January 2014
  2. 2. Dr. M N M Bhutta Secure Socket Layer/ Transport Layer Security • Transport Layer Security (TLS) and its predecessors Secure Socket Layer (SSL) provides security (confidentiality & integrity) at transport layer in TCP/IP stack and at session layer in OSI model. • Client and Server should setup a TLS connection before communicating securely with each other. • It uses PKI for secure channel setup and exchanges symmetric session key. • Symmetric cryptography is used for main security operations. • SSL has been superseded by TLS. Current TLS version is 1.2 and TLS 1.3 is available in draft version. 2
  3. 3. Dr. M N M Bhutta Virtual Private Network (VPN) • VPN extends private networks across public network (internet). • Enables computer and network devices to send and receive data across public network as if they are on private networks. • Major implementations of VPN include OpenVPN and IPsec. 3
  4. 4. Dr. M N M Bhutta Firewall • A system to control the incoming and outgoing traffic based on applied rules. – Packet filtering can control the traffic e.g. source and destination IP addresses, port No etc. – The information about connection and packets can be used to filter the packets (e.g. packets passing for existing connections, new connection packets etc.) – The traffic can be controlled on all layers up to application layer (e.g. information about protocols can be used to filter the traffic like DNS, HTTP etc.) 4
  5. 5. Dr. M N M Bhutta Malwares • Common Malwares: 5
  6. 6. Dr. M N M Bhutta Malware Analysis/Reverse Engineering • Art of dissection of malware: – To provide information about intrusion/attack (what exactly happened). – The goal is exactly to find out: what a suspect binary program can do, how to detect it, and how to measure and contain its damage. • Host based signatures and network based signatures are used to detect malwares on computers and networks. • Most often malware analysis is performed on executable files using following techniques: – Basic and Advanced Static Analysis – Basic and Advanced Dynamic Analysis 6
  7. 7. Dr. M N M Bhutta Malware Analysis/Reverse Engineering – II • Basic Static Analysis – It is performed on executable file without actually running it and without viewing the instructions code. – It answers whether file is malicious, provide information about its functionality and some times to produce network signatures to detect malwares. • Advanced Static Analysis – It is performed by dissecting the malware executable by loading it into disassembler and looking into its instructions to find out what malware do. • Basic dynamic Analysis – It involves running the malware and observing its behaviour on the system in order to remove the files, produce effective signatures. • Advanced Dynamic Analysis – It involves debugging the internal state of malicious executable. 7
  8. 8. Dr. M N M Bhutta Penetration Testing/Ethical Hacking (Web and Infrastructure Hacking) • Penetration testing is legal and authorized exploitation of computer systems to make them more secure. • Penetration testing is performed in following phases: – Reconnaissance: collecting detailed information about system (e.g. all machines IP addresses etc. ) – Scanning: 1. Port Scanning (finding open ports on systems and services being run). 2. Vulnerability Scanning (finding known vulnerabilities for services running on the system) – Exploitation: Attacking the system for the found vulnerabilities. – Maintaining Access: After exploitation, creating a permanent backdoor for easy access to the system later on. – Reporting: Details about the found issues, detailed procedures and presenting solutions to mitigate the security issues found. 8
  9. 9. Dr. M N M Bhutta Digital Forensics (Computer & Network Forensics) • It is defined as application of science to law. • It is the application of collection, examination and analysis of data while preserving the integrity of data and chain of custody. • The process usually consists of following phases: – Collection: Identifying, collecting, labelling and storing data. – Examination: Assessing and extracting particular interest of data. – Analysis: Analysing the data using legally justifiable techniques. – Reporting: Reporting results of analysis (actions to be taken to secure against vulnerabilities, information about crime/attack etc) 9
  10. 10. Dr. M N M Bhutta Practice ! Don’t try at home and/or without required permissions
  11. 11. Dr. M N M Bhutta Thanks for listening ! »Questions ?