Security aspects

 Prevention means protection of our data and devices from illegitimate access 

Malware - it is used for malicious software. It's 

Intention is to damage hardware ,corrupt and steal data 

Types of malware - virus, worm, ransomware . Trojan horse

Virus - 

1. Virus term was coined by Fred Cohen in 1985

2. It is a piece of software for malicious activities

3. It spread through infected file.

4. Virus activate as soon as infected file is executed

Example- crypto locker, sasser. 

Worms - 

1. It is a malware 

2. Worm is standalone.It does not need a host program 

3. Worms are capable of working on its own,they do not need human triggering 

Ransomware -

It blocks the user from accessing their own data or threaten user to publish personal data and demand ransom 

Example - A ransomware 'WannaCry' in May 2017 infected computer s all over the world 

Trojan horse - It is a malicious software which looks like legitimate software but after installation it behaves like virus or worm 

Some Trojans provide backdoors for malicious software 

Spyware -

It is a malware which record and send information to other person without knowledge of the user 

Adware - adware displays online advertisement  advertisement.

Adware is created to generate revenue for its developer 

Keyloggers - it record the keys pressed by user on the keyboard and send this information to other person 

It send information  like password , emails,  

etc.  

Online keyboard Vs on screen keyboard - 

On-screen keyboard uses a fix qwerty keyboard which can be exploited by keyloggers whereas online screen keyboard 

Randomises the keylayout everytime. 

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Malware distribute modes -. Download from internet, through e-mail, network propagation ,through device  

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Type of hackers - 

1. White hat Hacker -  they are known as ethical Hacker. They use their skills to fix the issues related to security system.

2. Black hat Hacker - they do not have good intension ,they use their skills to disrupt security 

3. Grey hat Hacker - they hack system but they don't do this for money. They hack system for fun.

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DoS and DDoS - DoS in denial of services .

In this the attackers the web server overloaded the server and server is not able to provide sevice to the user, user think that website is not working In this way it damage the victim's organization.

DDoS is known as  disributed denial of services where attacker computer system are distributed across the world known as zombie systems 

They have malicious software known as Bot on Zombie systems.

HTTP Vs HTTPS - HTTP is known as hypertext transfer protocol . It is set of rules that govern  how data can be transmitted over WWW 

HTTPS means hypertext transfer protocol secure.  It send data more securly  over the network. It encrypt data before sending on network and data decrypts only at receiver's end. 

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Firewall - It is a network security system which can be hardware or software or combination of hardware and software 

It continuously monitor and control the incoming and outgoing traffic.

It has two types - 

Network firewall , Host based firewall

Network firewall - when firewall is placed between two or more network.

Host based firewall - when firewall is placed on a computer and monitor's the network traffic

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Cookies - Cookies is a small file which is send by server on the client's computer.

It is used by website to store browsing information

It is edited only by the website which create it.

Example - Session Cookies

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Antivirus - Software which is used to detect and remove virus. 

Sandbox detection, data mining technique, signature based detection, are some techniques of virus detection used by antivirus. 

Sandbox detection - it is a slow method but effective.In this  file is executed in virtual environment and observed for a possible malware 

Signature based detection -  in this antivirus works with the help of database called as 'Virus definition file'.  This method is not effective because virus has ability to change its signature. 

Heuristics- source code of a suspected program is compared to viruses pattern that is already known .

Realtime protection -  software continuously runs in the background and observe the behaviour of file 

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Spam - It is unwanted message or emails 

It is send by organization or individuals  and send repeatedly  advertisement links and invitation emails to large number of users 

It waste the memory.

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Snooping -  it is a software package which is used to listen conversation secretly in network.

Sometime it is also used by network administrator for trouble shooting  in the network.

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Eavesdropping - monitoring of conversation between two entities over a network is called eavesdropping.

It happens in real time