Malware (Malicious software)

"Malware" is a generic term used to describe any program or file that is harmful to a computer. Malware includes computer viruses, but the term additionally refers to adware, spyware, and even web sites that try to install harmful software when you visit. Older antivirus programs do not provide adequate protection against these security threats, so be sure you are using the latest version of Symantec AntiVirus.

How computers become compromised with malware

Your computer can be compromised by many of the threats listed below:

• Email attachments, even ones that seem to be from people you know
• Flash drives or other removable media
• File sharing "P2P" (peer-to-peer) software
• Web links within in email messages
• Malicious macros (automated actions or commands) within Office files like Word documents or Excel spreadsheets
• Free and shared software like "weather bugs," music players, and other little web utility programs
• Browser pop-up windows that urge you to click on links
• Instant Messaging
• Software downloads from illegal pirated software sites

Symptoms of a malware or spyware infection

• Your computer suddenly starts to behave strangely, requires frequent restarts, or begins showing pop-up ads that aren't related to the website you're visiting.
• Your browser settings have suddenly changed without your consent. Often malware changes the home page setting on your browser to a different site than your normal preference.
• Additional browser toolbars appear at the top of your browser windows.
• Your computer seems unusually sluggish and unresponsive.
• Your firewall and antivirus programs are frequently turned off automatically.
• You are unable to stop the excessive pop-up windows that appears from nowhere.
• You find new programs in the add/remove programs of your control panel which you don't ever remember installing.
• You get a lot of bounced back email and see evidence of emails being sent without your knowledge.

What you can do about malware

• Install and run antivirus software with the latest definitions.
• NOTE: Spyware in particular does not currently appear to be an issue with Macintosh OS X, but the Mac is NOT immune to malware threats, so always keep your antivirus software up-to-date.
• Only open attachments from a trusted sender. Even then, remember that "To:" and "From:" email headers can be spoofed, so try to confirm with the sender if you have suspicions about an attachment.
• Don't browse dubious or untrustworthy websites.
• Only install software from trusted sites and familiar software companies. Think before installing any software from an untrusted source, weigh the risks and benefits, and read the fine print.
• Be aware of the security risks of installing peer-to-peer (P2P) file sharing software, or Instant Messaging software. P2P software is also a major vehicle for identity theft schemes.

What can you do to prevent your computer from becoming infected?

While there is no method that can 100% guarantee that your computer will be not be infected with malware, there are steps that you can take to lessen the probability of this happening.

• Install antivirus and anti spyware programs from a trusted source
• Update software regularly
• Use strong passwords and keep them secret
• Never turn off your firewall
• Use flash drives cautiously
• Don't be tricked into downloading malware  (e.g, phishing, email attachments etc)

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Related topics

• Virus protection
• Spyware programs

Related online resources

• OnlineOnguard.gov - Minimizing malware
• Symantec Virus Encyclopedia
• Symantec Hoax Encyclopedia