Symtoms of Computer Infections

Sometimes, there are obvious signs that there is malware on your computer, sometimes there is not. At first, the signs are subtle; your Computer seems to have a mind of its own. Malware programs contact other computers for various purposes and each of them is a program of its own, therefore they use system resources such as CPU cycles, memory and an Internet connection. A sudden change in how your computer is running could be a sign of spyware or adware. The really hard part about spotting spyware symptoms is that they often appear to be normal Web or computer operations. So, you may not recognize them as a symptom.

Below are some of the symptoms that may reveal that you have malware operating on your computer. Note that a few of these symptoms could also be from a number of other reasons.

Spyware Symptoms – Symptoms that may indicate a Spyware infection

One of the oldest and most common spyware tricks is to automatically change your Web browser's default or start-up homepage – the page that first appears when you start your browser or click the "home" button.

You end up in a same strange site, whenever you perform a search.
Your firewall and antivirus programs are frequently turned off automatically.
You cannot access security related Websites or cannot update your anti-virus definitions.
Your network connection's activity lights blink a lot, when you are not actively doing anything on the internet.
You are unable to stop the excessive popup windows that appears from nowhere.
Your computer (not just your connection speed) slows down significantly whether online or offline.
Strange icons and new shortcuts lurking in your taskbar, system tray or on your desktop.
You find new programs in the add/remove programs of your control panel which you don't ever remember installing.
You notice an unusual amount of new favorites and are not sure how they got there.
Strange problems occur within windows, (performance issues, programs not working as they should, etc)
You are redirected to a strange site instead of 404 error page, when a web page isn't found.
You get frequent alerts from your firewall about an unknown program or process trying to access the internet.
You get a lot of bounced back mail and see evidence of e-mails being sent without your knowledge.
Your browsing speed becomes very slow since you installed the "ultimate search companion".
Strange and unexpected toolbars appear in your web browser and you don't know how it got there.
Your phone company charges you for '1-900' phone calls you didn't make.
When you try to open spyware eradicating programs like Spybot S&D, Adaware or windows programs like Task manager, Regedit and Msconfig, they just pop up on your screen momentarily and disappear.
The Java console appears in your task bar when you hadn't run any Java software recently.

Virus Symptoms – Symptoms that may indicate a virus infection

Hoax email messages about viruses are extremely common. Messages which suggest that just reading an email message (rather than opening an attachment) can wipe your hard disk or your BIOS usually are hoaxes, as are messages which say "Please send this email to all your friends".

If you receive virus warning messages which don't come from a known expert, the best response is to consult the website of a well-known anti-virus company. Useful information about virus hoaxes is maintained by McAfee, Nortons, Vet, and Sophos.

Some common symptoms that could indicate your system's been infected are:

Unusual messages or displays on your monitor
Unusual sounds or music played at random times.
Your system has less available memory than it should.
A disk or volume name has been changed.
Programs or files are suddenly missing.
Unknown programs or files have been created.
Some of your files become corrupted or suddenly don't work properly Another method you can use to detect viruses is to monitor the byte size of the programs installed on your hard drive, particularly .exe and .com files. If you notice any unexplained change in file sizes, this is a good indication that your system has become infected. This can be a difficult and tedious method of checking your system, however, and installing anti-virus software is a better alternative.
Trojan Symptoms – Symptoms that may indicate a Trojan infection.
Your computer screen flips upside down or inverts.
Your wall paper or background settings change by themselves.
Documents or messages print on your printer by themselves.
Your windows color settings change by themselves.
Your screen saver settings change by themselves.
Your right and left mouse buttons reverse their functions.
Your mouse pointer disappears.
Your mouse moves by itself.
Your mouse starts leaving trails.
Your Windows Start button disappears.
Your computer starts reading the contents of your computer clipboard.
Your Task bar disappears.
Your computer shuts down and powers off by itself.

How to detect malware symptoms

If your computer starts to behave strangely, you might be experiencing spyware symptoms or have other unwanted software installed on your computer. Here are a few tips on how to detect malicious software:
I see pop-up advertisements all the time. Some unwanted software will bombard you with pop-up ads that aren't related to a particular website you're visiting. These ads are often for adult or other websites you may find objectionable. If you see pop-up ads as soon as you turn on your computer or when you're not even browsing the web, you might have spyware or other unwanted software on your computer.
My settings have changed and I can't change them back to the way they were. Some unwanted software can change your home page or search page settings. Even if you adjust these settings, you might find that they revert back every time you restart your computer.
My web browser contains additional components that I don't remember downloading. Spyware and other unwanted software can add toolbars to your web browser that you don't want or need. Even if you remove these toolbars, they might return each time you restart your computer.
My computer seems sluggish. Spyware and other unwanted software are not designed to be efficient. The resources these programs use to track your activities and deliver advertisements can slow down your computer and errors in the software can make your computer crash. If you notice a sudden increase in the number of times a certain program crashes, or if your computer is slower than normal at performing routine tasks, you may have spyware or other unwanted software on your machine.