IA Syllabus 2017 Topic Security

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Information about IA Syllabus 2017 Topic Security

Published on September 25, 2017

Author: onlinejobstudy

Source: authorstream.com

slide 1: NETWORK SECURITY IA Preparation 2017 This document covers the network security theory part of IA syllabus. www.onlinejobstudy.com Type your text This Document www.onlinejobstudy.com slide 2: Security IA 2017 1 | P a g e o gain access to private computer systems. It can appear in the form of :- o code o scripts o Active content and other software. Malware is a general term used to refer to a variety of forms of hostile or intrusive software. Classification Computer Viruses Ransomware Worms Trojan Horses Rook-kit Key loggers Dialers Spyware Malware: What is Malicious Software  Malware short for malicious or malevolent software is software used or programmed by attackers to :- o disrupt computer operation o gather sensitive information without the knowledge of the user  Adware  Malicious BHO’s  Rouge Security Software  Backdoors www.onlinejobstudy.com slide 3: Security IA 2017 2 | P a g e Figure: Malware different types Short note on Computer Virus Virus Worm and Trojan horse  People often think worm or Trojan horse as a virus. While the words Trojan worm and virus are often used interchangeably they are not exactly the same thing. Viruses worms and Trojan Horses are all malicious programs that can cause damage to your computer but knowing differences among can help you better protect your computer from damaging effects.  Computer Virus: o A computer virus attaches itself to a program or file enabling it to spread from one computer to another leaving infections as it travels. Like a human virus a computer virus can vary in severity: some may cause only mildly annoying effects while others can damage your hardware software or files. Almost all viruses are attached to an executable file which means the virus may exist on your computer but it actually cannot infect your computer unless you run or open the malicious program. o It is important to note that a virus cannot be spread without a human action www.onlinejobstudy.com slide 4: Security IA 2017 3 | P a g e such as running an infected program to keep it going. Because a virus is spread by human action people will unknowingly continue the spread of a computer virus by sharing infecting files or sending emails with viruses as attachments in the email.  Worm Write once read many o A worm is similar to a virus by design and is considered to be a sub-class of a virus. Worms spread from computer to computer but unlike a virus it has the capability to travel without any human action. A worm takes advantage of file or information transport features on your system which is what allows it to travel without any human action. o The biggest danger with a worm is its capability to replicate itself on your system so rather than your computer sending out a single worm it could send out hundreds or thousands of copies of itself creating a huge dangerous effect. One example would be for a worm to send a copy of itself to everyone listed in your e-mail address book. Then the worm replicates and sends itself out to everyone listed in each of the receivers address book and the manifest continues on down the line. o Due to the copying nature of a worm and its capability to travel across networks the end result in most cases is that the worm consumes too much system memory or network bandwidth causing Web servers network servers and individual computers to stop responding. In recent worm attacks such as the much-talked-about Blaster Worm the worm has been designed to tunnel into your system and allow malicious users to control your computer remotely.  Trojan horse o A Trojan horse is full of as much deception as the mythological Trojan horse it was named after. The Trojan horse at first glance will appear to be useful software but will actually do damage once installed or run on your computer. Those on the receiving end of a Trojan horse are usually cheated into opening them because they appear to be receiving legitimate software or files from a legitimate source. o When a Trojan is activated on your computer the results can vary. Some Trojans are designed to be more annoying than malicious like changing your desktop adding silly active desktop icons or they can cause serious damage by deleting files and destroying information on your system. Trojans www.onlinejobstudy.com slide 5: Security IA 2017 4 | P a g e are also known to create a backdoor on your computer that gives malicious users access to your system possibly allowing confidential or personal information to be compromised. Unlike viruses and worms Trojans do not reproduce by infecting other files nor do they self-replicate. Best Tips to Defend Against Viruses and Worms We must safeguard our PC. Following these basic rules will help us protect from malicious attacks  Protect your computer with strong security software and keep it updated o Use of software such as :  Anti-Virus and  Anti-Spyware Would keep our pc safe for malicious attacks. o Besides this we must also update the definitions of our antivirus anti- spyware so that it can detect new threats.  Use a security-conscious Internet service provider ISP that implements strong anti- spam and anti-phishing procedures.  Enable automatic Operating System updates or download Microsoft®updates regularly to keep your operating system patched against known vulnerabilities. Install patches from other software manufacturers as soon as they are distributed. A fully patched computer behind a firewall is the best defense against Trojan and spyware installation.  Use caution when opening attachments. o Configure your anti-virus software to automatically scan all email and instant message attachments. o Make sure your email program doesnt automatically open attachments or automatically render graphics and ensure that the preview pane is turned off. o Never open unsolicited emails or attachments that youre not expecting— even from people you know.  Be careful when engaging in peer-to-peer P2P file-sharing. o Trojans hide within file-sharing programs waiting to be downloaded. www.onlinejobstudy.com slide 6: Security IA 2017 5 | P a g e o Use the same precautions when downloading shared files that you do for email and instant messaging. o Avoid downloading files with the extensions .exe .scr .lnk .bat .vbs .dll .bin and .cmd.  Use security precautions for your PDA cell phone and Wi-Fi devices. o Viruses and Trojans arrive as an email/IM attachment are downloaded from the Internet or are uploaded along with other data from a desktop. o Cell phone viruses and mobile phishing attacks are in the beginning stages but will become more common as more people access mobile multimedia services and Internet content directly from their phones. o Always use a PIN code on your cell phone and never install or download mobile software from an unknown source.  Configure your instant messaging application correctly. o Make sure it does not open automatically when you fire up your computer.  Beware of spam-based phishing schemes. o Dont click on links in emails or IM.  Back up your files regularly and store the backups somewhere besides your PC. o If you fall victim to a virus attack you can recover photos music movies and personal information like tax returns and bank statements. Data communication security:  When a computer is connected to a public network all the data transmitted through the Internet are exposed to the outside world. The issues are : o Authentication: The process of identifying an individual usually based on username and password. Ability of each party in a transaction to ascertain identity of other party. Below picture shows the concept : www.onlinejobstudy.com slide 7: Security IA 2017 6 | P a g e o Authorization: Is the process of giving individuals access to system objects based on their identity. Authorization involves granting or denying access to a network resource. Below picture explains authorization : o Secured data transmission  The following technologies support secured data communication o Proxy Server o Firewall www.onlinejobstudy.com slide 8: Security IA 2017 7 | P a g e o Virtual Private Network VPN  Proxy Server: o A Proxy server is a computer that keeps copies of recently accessed web pages. Whenever A Http request is sent by client the proxy server checks the cache. If the requested page is not available the proxy server sends the request to the corresponding server. The incoming responses are sent to the proxy server and stored for future requests from other clients.so the proxy server reduces the network traffic to the server. o Proxy server works by intercepting connection between sender and receiver. By blocking direct access between two networks proxy servers make it much more difficult for hackers to get internal addresses and details of a private network. A proxy server can also be one of the components of a firewall. o Proxy servers provide increased performance and security. In some cases they monitor employees use of outside resources.  Key Points: o Multiplexing outbound requests through a single connection o Prevent access from inside as well outside based on certain policy o It keeps copies of recently accessed web pages o Proxy server sends the request to the web server only if the page is not available in the cache. www.onlinejobstudy.com slide 9: Security IA 2017 8 | P a g e Figure: Proxy server All the requests from end user will be processed through proxy server  Firewall: o A system designed to prevent unauthorized access to or from a private network. o Can be implemented in both hardware and software. o Frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet especially Intranets o All messages entering or leaving the intranet pass through the firewall o Messages are examined and those that do not meet the specified security criteria are blocked. www.onlinejobstudy.com slide 10: Security IA 2017 9 | P a g e Figure Firewall: Request to WAN and LAN access has to pass through firewall shown above. If it violates the security policy then access is blocked that is shown by dustbin bock in the picture.  Type: Based on the function o Filter-based firewall: Based on the IP packet source address destination address and port numbers. Only header of IP packet is checked. o Proxy-based firewall: Looks at the packet content. Only intended type request will be allowed. Provides finer-level of access Figure: Real life Firewall:  VPN Virtual Private Network www.onlinejobstudy.com slide 11: Security IA 2017 10 | P a g e o Secure and private communication over public Internet o Companies use VPN to connect to customer’s network Web Security applications:  Encryption: o Encryption is a method by which information is scrambled to make it unreadable to everyone except the desired recipient o The scrambled data after encryption is known as cipher text o It prevents unauthorized users from reading or tampering the data o Encryption uses mathematical algorithms to scramble data.  Decryption: o To read the encrypted file the recipient must convert the encrypted data back into its original form. This process is known as decryption.  Secured Socket Layer: o The well-known implementation of encryption is Secured Sockets Layer SSL. o The combination of SSL at Transport Layer and HTTP at Application layer is called as HTTPS. o Secured Sockets layer is a way of authenticated and encrypted communication between clients and servers. It is a protocol developed by Netscape for transmitting information securely over an insecure network. It is universally accepted and used by web browsers and web servers for transmitting sensitive information.  Digital Signature: o By message authentication we mean that the receiver should be sure about sender’s identity. One approach to provide authentication is with the help of digital signature. The idea is similar to signing a document. Digital Signature www.onlinejobstudy.com slide 12: Security IA 2017 11 | P a g e provides the remaining three security services Authentication Integrity and Nonrepudiation. o Data integrity is the maintenance of and the assurance of the accuracy and consistency of data. o Nonrepudiation is the assurance that someone cannot deny something. Typically nonrepudiation refers to the ability to ensure that a party to a contract or a communication cannot deny the authenticity of their signature on a document or the sending of a message that they originated. www.onlinejobstudy.com Thanks Regards www.onlinejobstudy.com

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