Computer viruses

Computer viruses UNEVERSITY OF PALETINE IT COLLEGE • PREPARD BY: • Ahmed Abd El- ilah • Ahmed Abu Ghanima SUPERVISES BY: Mss: YasminAl-bobo

What is a Computer Virus??? Computer viruses are software programs that are written to a compatible harm another, or to spy on and control computer virus is a malicious program that spreads from computer to computer.

Threats • Hackers, malicious software, and poorly designed software • Threats may exploit vulnerabilities to cause harm to users. • The malicious software or intrusion attempts are the threats that must be defended against.

How does viruses invade your computer? • You have probably heard of some ways that virus can invade your computer. • Through email attachments • By clicking on a web link when surfing the web • By downloading a program that claims to be a game or cool picture • Compressed files (Zip, Cab, Arj, Rar) • Others?

Program Start Virus End How Does a Virus Work??? Prepender Trouble

How Does a Virus Work??? Appender PE Infector Overwriter

Types of Viruses • Trojans • Stealth Virus • Boot or system • Macro • Script • Multipartite • Worms

Components of Security • Back Up • Configure your software • Use Anti-virus

Evidence of the presence of viruses in the computer • [V  I*] and [MM] and vV H t, j  N • [[Pt = j] and [t = 0] and (t,j,…, t,j+|v|-1) = v]  • v’V, t’, t’’, j  N and t’ > t • [[j’ + |v’|)  j] or [(j + |v|)  j’]] and • [((t’,j’,…, t’,j’+|v’|-1) = v’] and • [t’’[t < t’’ < t’] and [Pt’’  {j’,…j’ + |v’| -1}]]

Configuring Explorer

Attachment Handling

Use Security Features!!

Computer viruses