Viruses & the Cure

Or

How to keep your System Safe

Contents

• What is a virus?

• Total Active Viruses

• Types of viruses

• Top 5 Current active Viruses

• Virus protection (how it works)

• Suggested Virus Programs

• Demo of Norton’s

What is a virus?

• A computer virus is a program written to alter the way a PC operates, without the knowledge of the user. A virus must meet two criteria:

– It will execute itself, and will place its own code in the path of execution of another program.

– It must replicate itself, and may replace other program files with a copy of the virus file.

Types of Recognized Viruses

• File infector - Infects programs

• Master Boot rec. - Infect system area programs

• Boot Sector - Infect system area programs

• Multi-partite - Infect programs and system programs

• Macro - Infect macros of programs (MSWord)

Trojan Horse (not a virus)

• An Imposter

• Do not replicate themselves (reason not a virus)

• May cause loss or theft of data

• Will be triggered if you open an email attachment

The Worm

• Replicates from system to system without copying a host file (a file that contains an active virus).

• Can be email or macro worms

• Email worm will automatically send an email with virus attached to every address in your address list

The Virus Hoax

• Email that describes a virus which is a hoax

• May suggest fix by removal of real file

• Usually asks you to forward the email to everyone you know

• Use Google.com (search engine) to search for possible hoax.

Total Active Viruses

• As of May 29, 2002 there are 61148 active viruses (Symantec web site)

• Approximately 300 new viruses are detected per week (Over 1500 per year)

Worldwide Activity

Top Virus Threats

Risk	Threat	Discovered	Protection
4	W32.Klez.H@mm*	April 17, 2002	April 17, 2002
4	W32.BadtransB@mm	Nov. 24, 2001	Nov. 24, 2001
4	W32.Nimda.A@mm	Sep. 18, 2001	Sep. 18, 2001
4	W32.Sircam.Worm@mm	July 17, 2001	July 17, 2001
4	W32.Hybris.Gen	Sep. 25, 2000	Sep. 25, 2000

*Note: Found and quarantined in May 2002

Risk Explanation

• Category 5 - Very Severe

• Category 4 - Severe

• Category 3 - Moderate

• Category 2 - Low

• Category 1 - Very Low

Antiviral program (how it works)

• Scans files on your PC and compare to virus signature database. Database must be updated frequently.

• Also looks for certain types of viral behavior (not for signature). May cause false positive.

• Scans In & Out emails (not on AOL)

Suggested Virus Programs

• McAfee - $29.95

• Norton’s (Symantec) - $29.95

• Kaspersky - $49.95

• Recommendation - Norton’s, because this program automatically updates signature database when you connect to the web

Norton’s Antivirus Program (demo)

• Status

• Scan for Viruses

• Reports

– Quarantined Items

– Activity Log

– Virus List

How to Protect your System

• Unless you leave your system on and have a scheduled task to scan for viruses, you must activate a virus scan approximately once a week