Malware

Malware (short for Malicious Software) is a broad term used to describe any software intended for some malicious purpose.  There are several types of Malware, but the ones we see the most often are Trojans, worms, and spyware.

Trojans

Trojans are malware that disguise themselves as legitimate programs to trick you into installing them.  Typically a website will offer free software (often a pirated version of licensed software, or a free game), and when the user installs it, they've in fact installed malware.

To avoid Trojans, we recommend you:

  • Stay away from peer to peer file sharing and bit torrent sites
  • Never open any unsolicited attachments you receive in email, especially those with the .exe file extension
  • Do not install any free software from companies you don't trust 100%

These precautions don't work in all situations, unfortunately.  The most common Trojans we see at UM are fake anti-virus programs.  They appear when you're surfing the web, and often crop up in Google image searches, though they are also sometimes inserted into the banner ads that run on legitimate websites.

When you click on a link to an infected site, a pop-up is triggered which informs you that your computer is infected with some frighteningly high number of viruses, and asks you to "Click Here" to remove the viruses.  Often the pop-up is disguised as an alert from Windows; however, it's just a regular web pop-up.  The difference is that if you click on this pop-up in any way, even to close it, the malware gets downloaded and installed on your computer.  It then pops up constantly, warning you that you have hundreds of viruses and instructing you to purchase the "Full Version" of the anti-virus software to remove them.

If you encounter one of these pop-ups, you should:

  1. CALL SNRE IT IMMEDIATELY!  Do not try to clear the pop-up yourself; do not try to run your anti-virus software.  Call SNRE IT.
  2. If you encounter a pop-up warning when the SNRE IT office is not open, or it appears on your home computer, TURN YOUR COMPUTER OFF by holding down the power button for 10 seconds or so.
  3. If you are unable to turn off the computer for some reason (e.g. you have models or calculations running, etc.), press CRTL-ALT-DEL on your keyboard, choose Task Manager, select your web browser from the Applications tab, and click End Task.

There's no way to completely prevent these Trojans from popping up, but there are a few things you can do to help reduce the risk:

  • Use Mozilla Firefox as your web browser.  Most infections seem to occur through Internet Explorer.  Firefox is a slightly more secure browser.
  • Ask SNRE IT to install Ad-Block Plus, a Firefox Add-on which prevents banner ads on websites from being displayed.
  • Avoid unknown or untrusted websites whenever possible.
  • Limit Google image searches as much as possible.  I realize this last point is extremely difficult, and I don't want to suggest that you should never use Google image search.  Just try to restrict it to work-related searches, not searches for new desktop backgrounds, etc.

Anti-virus software often doesn't prevent the installation of Trojans, since users often intentionally choose to install the software.  Most good AV programs will detect and remove Trojans after they are installed, unless the Trojan specifically disables the AV software. 

Worms

A worm is a self-replicating program that typically copies itself to each new writeable device plugged into a computer.  When a computer gets infected with a worm, the worm copies itself to each removable USB flash drive and external hard drive that gets connected to the computer.  When those removable drives are plugged in to other computers, the worm infects them, etc.

The worm usually performs some other function as well, known as its payload.  This could be installing software designed to turn your computer into a spam relay, illegal file sharing storage device, or bot to spread denial of service attacks.

The same precautions for avoiding Trojans apply to worms.  Also be cautious about who you allow to plug USB drives into your computer.  Many users' computers have been infected while at conferences overseas.  Anti-virus software is usually good at preventing worms from being installed on your computer, so having a good, up to date AV program on your computer is essential.

Spyware

Spyware often infects your computer behind the scenes while you're surfing the web.  Once installed, it collects data about you and returns it to the spyware author.  The data collected can include things as minor as what things you buy online or as major as the keys you hit when entering your usernames and passwords on the computer.  In addition to being intrusive and possibly dangerous, spyware can also cause your computer to slow down or become non-functional.

To avoid spyware:

  • Use a web browser other than Internet Explorer - Mozilla Firefox, Opera, and Google Chrome tend to have fewer vulnerabilities and are less likely to allow spyware to infect your computer.
  • Use caution when installing free software.  Many programs (especially games) are offered for free because they also install spyware which reports back to various marketing companies.
  • Stick to browsing reputable websites.
  • Install a good anti-virus program and keep it up to date.
  • You could also install and run a program such as Spybot or Ad-aware in addition to your AV program.