Downloading files from the internet is common, from movies and music, to games, photos and applications. Cyber criminals take advantage of the lure of instant access to the latest game, app or service by trying to trick us into downloading hidden malicious software, or malware.

Malware is designed by cyber criminals to infiltrate your computer and mobile devices to perform unauthorized activities and steal your information.

While downloading files from the internet is the most common way for your devices to be compromised, it’s not the only way. You might also infect your devices by clicking on attachments or links delivered to you in emails and text messages or by clicking on infected ads or links on websites.

There are different variations of malicious software. Some of the most common types include:

• Trojan horses – this looks like software that performs a desirable function, but once downloaded onto your computer, it may allow unauthorized access to your computer system.
• Spyware – also known as tracking software, spyware gathers information about you without your knowledge, collecting the personal information stored on your computer and monitoring the websites you visit and your login credentials.
• Scareware – this type of malicious software is designed to alarm you with pop-up notifications of a problem and to provoke you into downloading what you believe to be information or software that will help.
• Malicious apps – malware‑infected apps are designed to do a number of things such as stealing your personal information including financial information like credit card details, recording your phone conversations, subscribing you to services or sending text messages.

Once your device has been infected, your personal information could be exposed to criminals as the malicious software may allow them to monitor your keystrokes, scan through the files or open applications and transmit your information to others.

How will I know if my devices are infected?

Sometimes the signs of an infected device aren’t obvious – the malware could be running secretly in the background. In some cases though, there are a few telltale signs that your device has been infected with malware, such as the following symptoms:

• Your device might perform slowly, crash or freeze.
• You could have difficulty accessing the Internet.
• Your Internet browser may have changes to the toolbar(s) and could re‑direct you to other websites.
• Your data usage on your phone spikes.
• There is an app on your phone that you don't remember downloading.

How to protect yourself

The best way to protect yourself is to be careful about the information you download onto your devices. Here are a few more tips:

• Install anti‑malware, anti‑virus, anti‑spyware and Internet firewall tools purchased from trusted retailers or suppliers. Keep these programs enabled and continuously updated to protect your devices against malware.
• Be wary of downloading free apps, files, programs, software or screensavers. Only download apps from official app stores and retailers. Major app store platforms like Apple’s App Store and Google’s Play Store monitor content and routinely remove malicious apps. But you still need to be vigilant about the apps you download. Learn more here about how to spot the signs of phony apps.
• Never respond to pop‑up messages on a website or app that asks for your financial information. Slow down and don’t let urgent messages influence you. Always take the time to review the details carefully and research the facts before you take any action.
• Contact your bank immediately if you notice any charges to your bank account or credit cards that you don’t remember making.

If you think you may have inadvertently downloaded malware, disconnect all infected devices from your Wi‑Fi network to avoid infecting additional devices. Install anti‑malware software from a reputable retailer and scan your devices for malware. Seek out help from a computer security professional if you need assistance with cleaning your infected devices.