Week 11 - security

this topic was not supposed to be on Week 11, but I could not remember what week is this topic taught. so, let's just assume it is on week 11 as I have to put the topics in order. This week topic is on security!

networking security is becoming more and more important as people spend most of their time connecting with other people. we can have many attacks from any connection that you have in this world. therefore, there is a need to remember that this problems can be a serious matter if people choose to ignore it.

few examples of attacks a user may face:

1) Attacks against IP
- IP spoofing : a condition where one host stated that they have the IP address of another.
- IP session hijacking : the hacker can gain control to any type of actions that a user is doing. for example, while writing an email, a hacker can take command of the email thus manipulating it for their own benefits.

2) Data destruction
- this involves attacker just delete anything they want for their entertainment

there are a few protection that a user can provide to their computer to prevent this attacks :

1) Firewall
- with Firewall, we can control the information that goes in and out of our network.

2) VPN (Virtual Private Network)
- VPN's are a way to establish a "virtual" network on top of some already-existing network. This virtual network often is encrypted and passes traffic only to and from some known entities that have joined the network. VPNs are often used to connect someone working at home over the public Internet to an internal company network.

3) NFS (Network  File System) security
- many sites use NFS to serve home directories to users. therefore, anywhere they login, they will easily directed to their home files. it involves exporting the file systems.

simple precautions that a user can take to assist them if they are attacked :

1) always backup files so that if any of the documents are deleted, you will not be too depressed if you lose your important work.

2) keep your antivirus up-to-date so that your computer can repair any kind of viruses that are sent by this hacker a.k.a attacker

3) be familiar with all security services so in case of any attacks, you know what to do.


VIRUS


A computer virus can cause a lot of damage to files and softwares. here are a few viruses that we mostly heard:

1) WORM
- small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.


2) Trojan horse
-  is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk). Trojan horses have no way to replicate automatically.


3) Melissa virus (1999)
 it is so powerful that it forced Microsoft and a number of other very large companies to completely turn off their e-mail systems until the virus could be contained.