Depending on the type of pest that plagues your computer, it
may be very easy to detect an infection, if you know the
symptoms. Unfortunately, some of the most dangerous infections
(spyware and Trojans) can be very difficult to detect. That's why
most of the checking and removing of pests is done with software
designed to do just that. Nevertheless, there are several general
symptoms you ought to know:
Trojans, spyware and other pests use system resources, such as memory, CPU cycles and Internet connection.
There are many things that can slow down your computer, but if you know it well, you can detect changes in his speed. Of course, a computer may slow down by running several programs at the same time, or by running a resource-hungry application. On the other hand, the computers are machines, they do not slow down because are on bad mood. A sudden change of you computer speed may be a sign of spyware or adware.
If you receive a lot of bounced back mail, or see evidence of messages sent from your account without your knowledge, it is possible that Trojan spamware is sending Spam from your computer. These programs are very annoying, as your friends may open these messages, believing that you sent them... and may get infected. Even if you computer is not being used to send Spam, a Trojan can steal all the addresses of your friends, and send them to a spammer.
Noises and misterious activity:
Victims of some Trojans report CD drives opening and closing mysteriously, or programs running and closing without reason. Your computer is accessing the hard drive often, even though you are not doing anything? Is there an unknown icon in your Windows system tray? Or perhaps your Internet connection shows activity, although you are not using it. These are all signs a program may be up to no good in the background.
Browser with its own will:
A very frequent symptom is the change of some browser settings. In some cases the browser changes its start page without reason, and it even refuses to accept a start page change. Another symptom is the redirection to a search page when you type an incorrect URL. These symptoms indicate that you are most possibly infected.
Pop-up ads: Legitimate or adware?
"pop-up" ads are new browser windows, opened automatically over your browser. The "pop-under" ads are similar, but they open behind your browser.
These ads are often legitimate publicity, served by the site that you are visiting. But they can be also a symptom of adware on your computer. Clicking on a rogue pop-up can lead to an infection or take you to a site where danger lurks.
Most legitimate pop-ups open over your browser when you visit a website. If the site is well known (ESPN, USA today, etc.), then the advertiser is usually legitimate and well known as well. In some cases, the title bar of a pop-up advertisement starts with something like "USAToday.com advertisement" so you know where the ad originated.
When you see a pop-up, ask yourself some
- Are you online? If the ad appears when you are using Excel, or some other application that does not use Internet, is possible that the ad is caused by adware.
- Did you just visit a Web site or open a new Web page? Most legitimate pop-up ads launch when you open a new page.
- Which site is visiting, and who is the advertiser? Many legitimate websites use these ads, but if you're treading in the dangerous waters of the Web, such as hacker sites and pornography, the pop-ups are more likely to be shady and deceptive and could lead to a site where spyware or adware lurks.
- The announcements are related to you recent web searches? Some spyware and adware programs use this technique.
By answering these questions you may suspect that there is some adware launching ads on your machine. If the ad looks suspicious to you, or appears when you are not using Internet, or advertises work at home or get rich quick-type messages, never click on it...
In our next article we will talk about the tools to identify spyware and eliminate these programs.
Please see our help file section for more articles, resources, information and tools.