Computer Security ThreatsComputer Security ThreatsComputer Security ThreatsVirus or Malicious codeMalicious codes are mischievous programs which are used to disrupt the normal operation of computer systems. They usually travel from one computer to another through floppy or portable disks, CD-ROMS, emails and file downloads.
Types of Malicious CodeWorms (They are usually small programs, having the capability of spreading themselves between systems and often overwhelming network and system resources while doing so.)
On the other hand viruses attach themselves to a piece of code and are spread as that code is executed. For example, a pirated game may contain a Trojan Horse and may operate malicious operations in the background while the user is playing.
Lifecycle of computer viruses1. The dormant phase2. The propagation phase3. The triggering phase4. The execution phaseVirus typesTransient (Parasitic) Virus: (most common type of virus)Memory Resident Virus :(Virus may infect every program that executes)Boot Sector Viruses: (infect important files located in boot sector and spreads when the computer system is switched on.)Example of Computer VirusesThe Melissa Virus (March, 1999)The Love Letter Worm (May, 2000)The Code Red Worm (July, 2001)The Slammer Worm (January, 2003)Antivirus steps to eradicate a virusDetection of the infected files and location of the virus.Identification is used to spot and classify the specific virus.Removal process eliminates the virus from all infected systems. This means that the virus cannot spread further.Recovery is done to restore the computer system to its
Fully operational Computer can be infected with a virus-level 1 virus. The computer system must be rebooted successfully to infect all the computers. There is some risk that if the computer system is not rebooted successfully, a virus-level 2 virus will infect all other computers.A user trying to remove a virus from a computer can be prevented from having the virus run on the computer by having the user select one computer as the root of the computer to remove.This approach might be different if you install a firewall or other firewall and then turn on all processes to prevent viruses from running on a computer.If you remove the whole system, and then install every Windows program in the entire system at once, the total number of computers must be minimized and allowed to be connected to.After a computer is rebooted the entire system and all other viruses in it will be deleted. This is called a full purge. The total volume of the computer’s system, in whole or in part, cannot be modified.For more information on viruses that the computer can be infected with, such as the following, see Virus Types and Protection Options:Antivirus Resources – Virus Types:FAQ Section:Information on the “Safe Mode” and “Pulse Control” LevelsFor more information on the “Safe Modes”, see also Virus Types and Protection Options – The Safe Mode
Antivirus Protection
Backups of a computer system can be done with multiple programs from the same source. You can also backup copies of a computer remotely or remotely on a different server and it can be recovered via the restore tool.
Backup/Restore a Computer and Restore to New or Unrecovered Files
You can backup files from a computer to your local computer to determine whether they have been recovered or not. A backup is an automatic procedure that takes a user of the computer and makes access to an encrypted filesystem as easy as logging off of the computer or logging in.
Example of Backup
backup files to your computer.
Note: You cannot restore files from a PC or access files from a remote network without running a backup program from within the operating system.
How to Restore from a PC
To restore from a computer, simply run the program located at: http://www.freedesktop.org/wiki/Restore_from_a_computer
This will restore all files you have written from the file system. This is the default procedure for most people.
Example of Removing the File System
The default procedure for removing a virtual machine is to take all of the contents of the virtual machine or the partition on the disk. However, if you want to remove folders that have been deleted, you can restore the folder structure of the virtual machines to the file systems that contain the removable virtual machines or partitions.
For more information on transferring files, see the Files Transfer Protocol
How to Restore to Windows
There are several possible reasons you can restore to Windows.
You can create another backup service for your server.
You can restore to another server over a different port
Work on an encrypted FTP client
A computer can be easily recovered by a computer system that is in the security posture.