Note: This article has affiliate links.
It is safe to say that as long as there are computers, there will be computer viruses. It’s an inevitable risk that comes with owning a computer, much like the risk of catching a cold during the winter season or getting teary-eyed while cutting an onion. Of course, these references are not perfect, but you get the point.
Computer viruses are named after human viruses because of their ability to transfer from one infected file to another. However, unlike most human viruses, computer viruses are man-made. A computer virus is essentially a computer program designed to attach to legitimate computer programs and fulfill a malicious action. Some computer viruses corrupt your files, making them unreadable. Others hijack your web browser or corrupt your hard drive formatting; the list goes on.
In the case of smartphones, there are no programs that replicate like computer viruses, especially in Android devices. However, there are several other types of malware (malicious software) for Android and iOS devices. As expected, these programs are designed to cause harm to your files or some sort of discomfort to you.
You’ll soon know how computer viruses infect computers. There are different types of viruses; we’ll share with you some of them. You’ll also find out some of the attacks caused by viruses and other malware programs.
Using an antivirus package such as Norton or McAfee antivirus (two of the best antivirus for iPhones, Android phones, or PCs) can help you protect your devices from viruses and other malware programs, but taking some care when visiting the internet can make a difference. You’ll soon find out about some precautionary measures you can take.
How viruses infect your iPhone, Android phone, or PC
By the way, devices that cannot access the internet or install a program are not at risk of catching a virus, so if you have a phone that only makes calls, viruses shouldn’t bother you.
Computers and smartphones get viruses almost the same way. The problem usually starts after downloading a malicious program with a code to self-replicate and cause harm to your device. You can download a malicious program off the internet or through file sharing (Bluetooth, WiFi, and file transfer).
Being cautious when online is probably the best way to avoid viruses and other malware attacks, but using one of the best computer antivirus packages available, such as Norton or McAfee antivirus, can also help you protect your devices against these viruses.
Let’s review 5 common ways your iPhone, Android phone, or PC can be infected:
Downloading infected email attachments or clicking on a spoofed URL
The virus gets into your computer or smartphone through your email (known as a phishing email). However, the virus only becomes active after you’ve downloaded and opened the attachment in the email or clicked on a spoofed URL.
Text-only emails don’t carry viruses unless they have an embedded link to a spoofed website.
These phishing emails are designed to look legitimate; even a seasoned security expert can fall for the bait, so it’s important to properly study an email before clicking on a link or downloading an attachment. You can find several phishing email examples on the web.
Emotet is an excellent example of a virus delivered through phishing emails. It is designed to cripple IT systems. In some cases, the malware is tweaked to demand ransom from its victims.
Luckily, email service providers like Gmail are proactive with email security. An email can be listed as spam even before it gets to your inbox if it exhibits scammy qualities; however, it is not infallible.
This is a common way of exchanging files between laptops or from a laptop to a phone. Sadly, when you connect removable media to your phone or laptop, you risk getting a virus. If a file on the removable media is infected, it will then infect your device. And this cycle continues until the removable media is scanned and treated for viruses.
Rubber Ducky is an example of a virus that travels on USB drive and infects your PC by encrypting your files. A USB drive with Rubber Ducky malware comes with preinstalled keystrokes to self-activate once it is plugged to a computer. Rubber Ducky can encrypt your files with your knowledge.
Many computer programs and smartphone apps are delivered over the internet. Depending on your operating system, you may download most of your apps from Google PlayStore, iOS App Store, Microsoft Store, or Mac Apple Store. Sadly, in recent times, security experts have found some malicious apps on these official platforms.
Android users are particularly vulnerable due to the open-source nature of the Android platform, but Google has been equal to the task. The American multinational company removes malware apps on Google PlayStore as soon as they pop up.
As it turns out, apps on official app stores may not be as risky as those downloaded off the internet, on random websites promising you unrestricted access to a paid app. Several viruses can be attached to free downloads or cracked apps. Once they are installed, the contaminated programs execute the hacker’s code.
It is then advisable to stay away from illegal downloads because these files are transferred peer-to-peer or uploaded without verification, unlike apps on official platforms.
To be clear, downloading from third-party app stores falls under internet downloads. Third-party platforms have far less restrictive app approval policies than official stores like Google Play and the iOS App Store, so they have double risk. In 2020, 9game.com was listed as the most dangerous place to download programs. According to RiskIQ, 9game hosted over 60,000 malicious apps in 2019 and contained more malware than its competitors.
For example, VMOWO City: Speed racing 3D was removed from Google and flagged as a malicious app, but it is still on 9game. Like several other apps banned from Google PlayStore, VMOWO City: Speed racing 3D is classified as a riskware. This type of malware is used to bombard the phones of unsuspecting gamers with ads.
This risk arises when software has a security hole – an exploitable weakness in its code. When hackers discover this flaw, they exploit it by adding a code to the program (also known as a zero-day vulnerability). As expected, these extra codes allow the hacker to execute a malicious action (also known as a zero-day attack).
Zero-day vulnerabilities can be found in any app, popular and not-so-popular, small and large-scale apps like Microsoft Word, Adobe Flash Player, Zoom, etc…. Just recently, Adobe warned of a critical vulnerability in Adobe Acrobat Reader that has been exploited to target Adobe Reader users on Windows.
According to Adobe’s report, the vulnerability (CVE-2021-21017) has been exploited in “limited attacks.”
Similar incidents have occurred in the past, and it takes a while before the holes are discovered. Hackers find these flaws by actively looking for them in popular apps for malicious purposes – it’s a full-time job.
Consequently, software makers like Microsoft and Google routinely check their products for security holes and release updates to fix issues. They also upgrade the security of their products to match recent virus threats, so it is recommended to use apps from well-known software makers. And that is as important as getting the latest version of these apps once they are available.
Social media and online ads
Hackers exploit social media’s friendly ambiance to share spoofed links to unsuspecting people. It just so happens that this trick is super effective as thousands of people have lost their accounts or other sensitive information after clicking a link shared on social media.
If you think about it, you can understand why this trick is effective. It is easy to assume that everyone on social media is trying to connect by sharing an interesting video. However, that is not the case. Hackers use fake social media accounts to share spoofed links. Recently, a trending Facebook video titled “IS THIS YOU” was flagged as a login stealer (key logger).
The same trick is applied to online ads. In most cases, hackers publish verified and legitimate ads on popular websites before replacing the link with a spoofed link. So it is vital to check the link address before interacting with a website.
Types of viruses
When a virus gets into a computer or smartphone, it executes the virus developers’ command, and that can be anything from encrypting your files to request for a ransom, to installing apps and showing random ads, or adding your computer to a network for brute force attacks.
In the tech world, viruses are classified based on their activity on your computer. Classification helps experts narrow down the primary target areas of a virus and the best remedial solution. Some of these virus types are the following:
Before discussing further, note that the term “virus” refers to malware that modifies legitimate programs in a way that when the program executes, the virus is also executed.
With that in mind, there are approximately 8 types of computer viruses. Each has a unique name and mode of operation (impact on your device).
Boot Sector Virus: This virus was common in the early days of computers when users had to boot from a floppy disk or external media. As its name suggests, a boot sector virus affects the boot sector, making start-up impossible without removing the virus. Luckily, the boot sector virus is not much of a threat as modern PCs can boot without a floppy disk or external device.
Some popular boot sector viruses include NYB (also known as B1), Form, Monkey, and Stoned.
Browser Hijacker: This virus infects your browser and redirects you to a website you didn’t request. Some browser extensions behave this way, which is a red flag. Any software that hijacks your browser without your permission is capable of worse.
Resident virus: If you’re a fan of the resident evil series, you must have read the heading with a grin. Like the zombies in the movie/games, the resident virus is a tough kill. Unlike other types of viruses, a resident virus installs itself in your computer memory. This allows it to work even after the infected files have been removed.
In some extreme cases, especially when you have a weak antivirus, a resident virus can infect files of your antivirus software. You need a special tool to remove it. So it is vital to use one of the best antivirus software/tools on the market, such as Norton or McAfee.
Meterpreter Trojan is an example of a resident virus that runs in computer memory without writing itself to disk.
Direct-action virus: A direct-action virus infects programs on your system but does not install itself to your memory. Depending on the hacker’s command, a direct-action virus will infect EXE or COM files. However, a direct-action virus is easier to remove than a resident virus.
An example of a direct-action virus is the Rugrat-B virus; it attacks 64-bit Windows.
Multipartite virus: While some viruses have a defined method of attacking a legitimate program and affect a victim, multipartite viruses infect in different ways and take different actions. A multipartite virus, such as Invader, can infect the boot sector and program files, making them difficult to remove. Even if you remove the virus from your program files, it will reappear as soon as you reboot your system.
Polymorphic virus: Experts at Symantec agree that polymorphic viruses are extremely difficult to remove because of their design. A polymorphic virus changes its binary pattern (signature) every time it infects another program. As a result, regular antivirus software struggle to track down the virus and eliminate it.
This is not an exhaustive list of the types of viruses in existence. Over 450,000 new malware programs pop up every day! However, many viruses have a similar architecture to the viruses mentioned above.
Five of the most dangerous computer virus attacks
History has taught us that computer viruses can cause untold economic damages. The impact of a virus depends on its design. Some of the most dangerous computer virus attacks in the last decade were caused by ransomware, trojans, and viruses.
ILOVEYOU is a decorated member of the “worst computer virus” hall of fame. It infected over 10 million computers and caused about $15 billion in damages. Surprisingly, the virus isn’t complex by today’s standards, but it had an irresistible appeal. The developer disguised the virus as a love letter from one of its victims’ contacts and spread it via email. The virus was concealed in the attachment “LOVE-LETTER-FOR-YOU.TXT.vbs.”
By clicking on it, a Visual Basic script (a programming language that lets programmers change code) was launched, and the virus began overwriting random files on the user’s computer. The worm also replicated itself and distributed copies to all contacts in the user’s address book.
ILOVEYOU infected over 10 million Windows PCs. The unexpected rush generated by the “love” bug forced the Pentagon, the British Government, and the CIA to shut down their mail systems altogether.
Tiny Banker Trojan
Tiny Banker Trojan (TBT) is a virus that targets financial institutions. It was discovered to have infected more than 24 large banking institutions in the United States, and it is based on a modified and scaled-down version of another virus known as Banker Trojans.
TBT infects the system and browser using different techniques, and it then retrieves the data transferred between you and the banking website. Once you log in, it produces a fake pop-up asking for login credentials while utilizing the original logo and the name of the actual website.
CryptoLocker ransomware encrypts files on Windows systems and then demands a ransom payment in return for the decryption key. It initially appeared in September 2013 as part of a persistent onslaught that lasted until May of the following year. CryptoLocker duped victims into downloading malware files attached to emails.
The Zeus computer virus is an online stealing tool that is reportedly responsible for 44 percent of all banking malware assaults. Before it was discovered, Zeus had infiltrated 88 percent of all Fortune 500 businesses, 2,500 organizations in total, and 76,000 machines in 196 countries by that point.
The Zeus botnet was a collection of applications that collaborated to take control of machines for a remote “bot master.” It was invented in Eastern Europe to move money to hidden bank accounts.
Reign was a highly sophisticated virus used by the US government to spy on citizens. The virus spreads via infected flash drives and bogus web pages, and it has a Trojan Horse at its heart.
As soon as it enters your system, Reign begins installing additional malicious applications that monitor your computer and provide a detailed report to the creator of the virus – the NSA.
It took some time for antivirus software to notice its presence, during which time hundreds of accounts were hacked.
Is your iPhone, Android phone, or PC virus ready?
To make your smartphone or computer virus ready, you need to install a virus watchdog, such as Norton or McAfee (two of the best antivirus for iPhones, Android phones, and PCs), which is an antivirus with real-time protection features that scans existing and incoming files for traces of recorded viruses.
Installing an antivirus is one of the best ways to protect your PC or smartphone against viruses. However, the antivirus you choose makes a difference. As mentioned earlier, some viruses can nest in your antivirus folder, which means it may remain undetected.
Your preferred antivirus for your computer and smartphone should offer high-quality protection and real-time virus threat updates.
Without question, viruses are a threat to everyone with computing devices, PCs or smartphones. And as computers become integral to our lives, the potential of viruses causing more harm increases.
The only way to avoid losing your data or computer to a virus is to learn about them and the best ways to protect your device.
It can take physical and digital effort to keep your device safe. You shouldn’t download cracked software or download apps from unregulated websites/platforms. Also, you have to avoid plugging unscanned USB drives and other removable media into your computer. The same caution should be applied to clicking links on social media or in emails and downloading email attachments.
That said, physical actions won’t insulate you from all types of virus threats. You need top-rated antivirus software to protect your computer from any threat.
Norton antivirus offers top-notch security for a reasonable price. With as low as $84.99 ($34.99 promo price), you can get virus protection for one year under the Norton Antivirus Plus plan.
Norton, one of the best antiviruses on the market, is an industry leader. It doesn’t just provide tools to remove viruses; you also get tools to prevent hacks and ensure online privacy. Norton’s smart firewall is solid hackproof protection for your PC any time. It doesn’t get better than this.