Made by : Mohamed kullab DR. Sanaa el sayegh

 Most personal computers are now connected to the Internet and to local area networks, facilitating the spread of malicious codelocal area networks  Today's viruses may also take advantage of network services such as the World Wide WebWorld Wide Web Introduction

History blush  The Creeper virus was first detected on ARPANET, the forerunner of the Internet in the early 1970s.ARPANET It propagated via the TENEX operating system and could make use of any connected modem to dial out to remote computers and infect themTENEX  Traditional computer viruses emerged in the 1980s, driven by the spread of personal computers and the resultant increase in BBS and modem use, and software sharingBBSmodem

Virus definition  computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the usercomputer program  A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or the Internet

Viruses  Viruses are sometimes confused with computer worms and Trojan horses. A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a file that appears harmless. Worms and Trojans may cause harm to either a computer system's hosted datacomputer wormsTrojan horses

Viruses  Some malware is programmed to damage the computer by damaging programs, deleting files, or reformatting the hard disk. Other malware programs are not designed to do any damage, but simply replicate themselves and perhaps make their presence known by presenting text, video, or audio messages

Detection and prevent  many big companies of computer work against this problem.  there is several software's done to detect and prevent all types of viruses and spy ware.

Detection and prevent  some of these software’s  Kasper sky.  MacAfee.  Norton.  A vast.  AVG.

Points take in counts  Do not open any files attached to an from an unknown, suspicious or untrustworthy source.  Do not download any files from strangers.  Do not open any files attached to an if the subject line is questionable or unexpected. If the need to do so is there always save the file to your hard drive before doing so.

Points take in counts  Update your anti-virus software regularly. Over 500 viruses are discovered each month, so you'll want to be protected. These updates should be at the least the products virus signature files. You may also need to update the product's scanning engine as well.  Back up your files on a regular basis. If a virus destroys your files, at least you can replace them with your back-up copy. You should store your backup copy in a separate location from your work files, one that is preferably not on your computer.