To many of us, asking “How do you get a virus on a computer?” in 2015 seems a bit redundant; by now, most people know not to open suspicious attachments, to maintain active antivirus software, and to heed their browsers’ warnings about suspicious websites. However, what many modern computer users don’t realise is just how sneaky viruses have actually become, and how the nature of what a “virus” is has changed—making these malicious programs more difficult to detect than ever.
The Changing Nature of Computer Viruses
Developing a modern understanding of the question “How do you get a virus on a computer?” requires first revisiting the question of why we get computer viruses at all; over the last decade, as ecommerce has become more and more prevalent, the aims of those developing viruses have changed.
Gone are the days when most viruses were the work of random cyber-bullies whose main goal was to destroy the recipient’s computer, making it crash repeatedly or otherwise go haywire simply for the sake of causing trouble. Today, most malicious software is not actually designed to co-opt the functioning of our computers (and other devices), but rather to lie quietly in the background, tracking behaviors, logging keystrokes, stealing data, planting ads, etc.—all for the sake of making a profit from our online behaviours. As such, stealth is the name of the game; the longer a virus can remain in place without being detected, the more revenue it can potentially generate.
While antivirus software can catch most malware, it’s difficult for the makers of these programs to stay abreast of each new virus and each new technique they employ to stay hidden. It’s therefore a good idea to review the following four surprising ways that malicious software can infect a computer and develop a browsing strategy which avoids encountering them:
Online ads, which were once simply a nuisance, can be very dangerous today, with attack ads appearing on even legitimate websites. How do you get a virus on a computer from an ad? According to Bari Abdul, head of consumer business at Check Point Software Technologies, you don’t even have to click on many of them. “Malvertisements — online ads with malicious code hidden inside them — are popular methods to spread malware. Without even knowing it, your computer is infected upon visiting the website, following the advertisement display.”
Social media seems “safe” to many people as it’s filled with friends, family, and reputable brands, but in reality, more than three-quarters of all malware and computer viruses are entering computers via social media. Always exercise caution when opening links via any social media site—those sharing them with you may have no idea they’re infected.
Even if your mobile device does not get infected itself, it can still harm your computer. “Cybercriminals have developed an app for Android phones, which they posted on Google Play labeled as a utility app,” says Benjamin Caudill, co-founder of Rhino Security Labs. “What it really did, however, was load up the phone’s memory with malware. The next time that phone was connected to a computer, the malware would activate and infect the computer.”
Visiting Suspicious Websites
This one should not really come as a surprise, yet many people still surf websites they know are not entirely above board (torrent hosting sites, sites which claim to let the user watch movies for “free”, etc.) while expecting their antivirus software to warn them of any threats. In reality, however, this doesn’t usually work—these sites tend to contain the most vicious, up-to-date and hard-to-detect malware, making them a minefield of hidden viruses.