Viruses & Spyware

A Module of the CYC Course – Computer Security

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Malware

• Viruses and spyware are often referred to as malware, short for malicious software.

• Malicious = vicious or mischievous• A virus uses your computer as it likes. It can

interfere with your computer use. It can damage files or software.

• Spyware uses your information. It can interfere with your computer use. It can steal your personal information.

Purpose

• Why would someone create a computer virus or spyware?– Vandalism– Money

Bogus Link Example

• Why should you not trust a message such as the one below, even if it comes from a friend?

Bogus Chat Message

• This one is trickier. Why not trust these chat messages?

How Computer Viruses Work• A virus can spell doom for your computer.• Viruses- A small piece of software that piggy

backs on real programs.• E-Mail Viruses- an email virus travels as an

attachment to email messages.• Trojan horses- A Trojan Horse is simply a

computer program . • Worms- a worm is a small piece of software

that uses computer networks and security holes to replicate itself.

How Viruses & Spyware Spread

• User clicks on an email attachment that downloads a virus or spyware.

• User clicks on downloadable file on a website that downloads a virus or spyware.

• User clicks on link in an email, on a website or on a social network. The link takes user to a website that attacks browser and forces virus or spyware download.

How Spyware works on your Computer

Symptoms

• Homepage changes (and you did not change it!)• A lot of pop-up windows you cannot stop.• Unexpected toolbars show up.• Redirected to sites you did not request.• Search results are provided by a different search

engine than you used.• Browser continues to crash inexplicably.• Files disappear (because they have been erased.)• Computer shuts down inexplicably.• Computer extremely slow.• A lot more junk email being received.

Prevention Tips

• Keep all your operating system and all software updated. Most virus and spyware attacks occur through security holes in popular software applications.

• For your browser, use Firefox, Chrome or Safari rather than Internet Explorer (IE). Because IE is so popular, virus and spyware creators target security holes in IE.

• Don’t click on any pop ups or ads offering you anything for free.

Free Anti-Virus & Spyware Software

• Use an anti-virus software that scans as files are downloaded. Do not use more than one anti-virus software that runs in real time. Recommended - AVG Free Anti-Virus

• Use a spyware software that scans periodically. Recommended - Spybot Search & Destroy and Malwarebytes

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Creative Commons License

• This module was created by Connect Your Community, a project of OneCommunity, funded by the federal Broadband Technology Opportunities Program.

• This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0