Computer Viruses

What You Need to Know to

Protect Yourself

Boot-sector infectors Attach to the “boot sector” of a disk

Macro viruses Attach to documents and spreadsheets

Types of Viruses File infectors

Attach themselves to programs

Other Malicious Programs

Trojan Horses You run the program on purpose, but it

does something more than you thought

Worms Like a virus, but spread via a network

without direct human intervention

How Much Damage?

Malignant Viruses Cause great damage that may or may

not be repairable

Benign Viruses Annoying, but not serious

Ways Viruses Spread Email attachments Shared files Floppy disks Infected documents and infected

word processors

Important: Viruses almost never spread between operating systems such as Mac

and Windows!

Spreading a Virus

Jake

EricChad DanielleBeckyAaron

Friend

Friend

Friend Friend

Friend

Friend

Ways to Prevent Viruses

A few examplesVirusScanAntiVirusF-ProtInnoculateIT

Install a virus scanner Keep it updated Many are free Set it to run automatically

Prevention (continued) Do not open email attachments you

were not expecting If downloading from internet, scan

with virus scanner before opening If you use Microsoft Word or Excel,

disable macros Keep your operating system and

programs up-to-date

Prevention (continued) Do not run random programs you

find on the internet

Turn off scripting in your web browser

Disable auto-run features in email programs

How Do I Know If I Have a Virus?

Virus checker gives a warning Strange messages appear Computer crashes more frequently Strange files you do not recognize start

appearing Files get bigger for no reason, or disk

space disappears for no reason Programs stop working normally

I Think I Have a Virus! Don’t panic! Stop using the computer Write down any strange messages

or warnings Do not reboot, open files, or run

programs Run your virus scanner Seek tech support help

Virus Warnings: Real or Hoax?

You receive a virus warning email Subject: “A Great Idea”

Will ruin hard drive, sound cards, & speakers Lies dormant in BIOS, even after reformat -

reappears after reformat Antivirus webpages indicate no fix for

problem Please forward to as many people as you

can! A very dangerous virus!

Virus Warnings: Real or Hoax?

Ask these common-sense questions: Did the warning come from a

trusted, knowledgeable source? Is there a link in the warning to a

site with more information? Is the virus listed on an antivirus or

hoax page? Does the warning make sense?