Malware in its various forms is nearly as old as the personal computer. Originally transferred from one computer to another via floppy disks, the proliferation of email and the Internet greatly accelerated the scale and speed of malware infection.

Yet, though malware is a real threat to personal computers, enterprise servers, and corporate networks, many people and organizations wait longer than they need to before they install anti-malware solution. Ideally, anti-malware software should be an integral part of setting up and configuring a computer or server.

But if you haven’t installed one, the following indicators of possible malware infection should prompt you to move with urgency in getting an anti-malware application.

1.   Slow Launch of OS or Applications

Without any problems, your computer should be fairly predictable and consistent in its behavior including response times.

If it used to take your operating system 10 seconds to fully launch once you power on the computer but it now takes 5 minutes, then malware is a probable cause. Similarly, if your desktop applications would launch fast but now take unusually long, your PC could be infected.

Deteriorating performance is a common symptom of malware since it creates an opportunity for the unwanted application to take over the system and/or extract sensitive data.

2.   Random Pop-Up Ads or Messages

This is typically an indication of adware or spyware infestation. The pop-ups are usually activated by clicking on Internet ads, an emailed link, or downloading free applications. Often, the message on the pop-up itself may seem relatively harmless. However, it’s meant to be a cover for stealing sensitive user information undetected.

The adware and spyware will illegally track your browsing habits and transaction activity in order to pick up passwords, credit card information, and banking details. Pop-up ads can be especially stubborn and aren’t always easy to remove from your system.

3.   The Blue Screen of Death (BSOD)

Does your computer suddenly freeze and then display the BSOD? This is unlikely to happen at random but rather when you are engaged in a particular activity such as launching a specific application, opening a given file, or trying to delete a certain folder.

It’s a sign of a system conflict and may be caused by malware that has interfered with settings or deleted a critical system file. It could also be due to orphaned registry keys left behind after you uninstalled a program. All of these are situations that can be resolved using anti-malware software.

4.   Shrinking Disk Space

If you regularly use your computer, chances are that the free disk space will slowly shrink as you store more files and add new applications. This is a natural progression and shouldn’t be a cause of alarm. You should, however, be concerned if your disk’s free space seems to be shrinking by large margins within a short period.

For example, if you had 60 percent free disk space yesterday but that has reduced to 30 percent by the next day, your computer could be the victim of a malware infection. Certain types of malicious applications will rapidly exhaust free disk space in order to cause the computer to crash.

5.   Unusually High Internet Traffic

The overwhelming majority of malware today is designed to use the Internet to propagate itself, relay information or (as part of a botnet) launch an attack against a remote target. This is why an unusual, unexplainable spike in Internet traffic is one of the most reliable indicators that something is amiss.

So if you are seeing a huge volume of data packets streaming through your Internet connection even when you aren’t engaged in any online activity, you should strongly consider installing and running anti-malware software on your computer.

Knowledge has always been the most effective weapon against malware and other forms of cyber attack. By staying on the lookout for these warning signs, you increase your odds of success in protecting your computer and network from malware. Unless these symptoms are caused by something else, a good anti-malware solution should clear them once it’s installed.