A computer virus has more in common with a viral infection that affects people. Like a flu virus, it tends to spread out by reproducing itself. Such a piece of programming code or an executable program, which is triggered by specific actions of a user and impacts the normal functioning of the computer.
Computer viruses do not appear accidentally. A virus is a specific type of malware, which is thoroughly developed by people, who are commonly referred to as hackers.
The purposes of creating viruses vary, but most frequently, hackers aim at making money by using malware. Viruses and other forms of malware steal sensitive data, destroy files, force users to watch paid ads, slow down the system, and do a lot of other annoying things. There are recorded cases when people lost millions of dollars just by catching a virus.
How Does a Computer Virus Work?
Viruses do not exist separately. They are always a part of something: a document, an app, or any other .exe file. The code of the virus is integrated into the file code. The virus can “hibernate” until the document is opened or a program is launched. In other words, you can store the file on your computer for some time without being infected. But as soon as you try to open it, the malicious code starts executing.
A virus attack can be impetuous and devastating, but sometimes it doesn’t have an immediately visible effect. You may even not be aware of the malware until it’s too late. Once the computer is infected, the virus can spread out to other devices connected to the network. If a business network is affected, the losses can number into hundreds of thousands.
While some viruses are quite innocuous, others are irritating. For example, they can force you to watch pop-up ads or slow down the system immensely. But the most dangerous viruses are the ones that steal data (logins, passwords, detail of financial transactions) or destroy/eliminate the files that are stored on the hard drive. In most cases, infecting causes financial losses.
How Do Computer Viruses Spread?
You can say that you are 100% protected from viruses only when your internet connection is off, and you never connect any USB-drives, disks, mobile phones, and other devices to it. In other words, your PC is isolated from any external interference. If it is not, you are vulnerable to viruses. There are several common ways of virus spreading.
It is, probably, the most popular channel of a computer virus transfer. Usually, viruses are hidden in attachments, which can look entirely innocent at first sight. Hackers successfully disguise infected .exe files as images, documents, PDFs, etc. By clicking on this file, you trigger the execution of malicious code.
The bad news is that even if you never open attachments to suspicious emails, you still can catch a virus by merely opening an email itself. There are ways to integrate malicious code in an HTML-code of a message body.
Instant messaging services are all the rage these days. Just some examples are Skype, Viber, WhatsApp, Facebook Messenger, Telegram, and so forth. Millions of people use them every day, and all of them are exposed. IM and social media viruses commonly come in the form of links, which also can look quite innocent. People tend to click on the links without any fear if the links are sent by someone they know well. But you must always bear in mind that your friend’s account could be hacked, so each link is potentially dangerous.
By File Hosting and File Sharing Services
These services are indispensable when you need to share a file with somebody. But they also serve a loophole for all types of hackers and swindlers. They upload an infected file (a document, an image, a video, an app, etc.) on the hosting and invite people to download it. The danger of this method is its wide coverage: everyone who downloads the file gets infected.
That said, some file sharing platforms are a little safer than others. Therefore, Google Drive offers an internal scanning for possible threats if the file size doesn’t exceed 25 megabytes. As for other services, such as DropBox, ShareFiles, etc., they don’t have any virus protection at all, so you should double-check the content you are going to download.
By Downloading Software
The easiest way to share a computer virus is via applications that are distributed in the form of executable files. The only problem is to make people download and launch these apps. Some hackers smartly resolve this problem. They show pop-up warnings about a virus attack detected. These warnings come in an aggressive form (bright colors, annoying beeping sounds, etc.)
Many users are frightened by this ad. To increase the effect swindlers use screaming headings like “Virus detected!”, “Your computer is in danger!”, and so on. Once you swallowed the bait, they offer you to scan your PC for threats by downloading the “best antivirus for Windows” right now. As a result, you download a fake app, which looks like an antivirus. As you’ve guessed, this is not an antivirus, but a piece of malicious software.
By Unpatched (Outdated) Software
The main reason why developers insist on the regular updating of their software products is the need for the security holes patching. Outdated products tend to be prone to viruses, and hackers take advantage of this vulnerability. By installing the latest security updates, you protect yourself from a range of potential threats.
Viruses can be spread via any outdated software products. So, users often suffer from using unpatched Adobe Reader, Microsoft Office, and other Microsoft apps. You need to keep in mind that your security is your responsibility. Don’t forget to download the current security updates from developers to minimize the risk of infecting.
By Plugging in an Infected Drive
USB-drives are a common source of viruses. When you plug in an infected flash stick, the virus is transferred to your PC. The most annoying thing is that the infection can stay in a dormant state until the next system reboot.
What are The Types of Computer Viruses?
Computer viruses come in a variety of forms. Different viruses behave in a different way. While some of them are relatively easy to get rid of, others can destroy the system.
Direct action viruses start working when you launch an infected file. If you download and save a malicious app, nothing will happen. But as soon as you run this app, the virus “wakes up.”
Resident viruses reside on the hard drive instead of being integrated into the executable code of a particular file. Usually, they come into action after the computer reloading.
Infected USB-drives commonly carry boot sector viruses. They are dormant until the nearest rebooting. As soon as you boot the system, the executing of the malicious code is triggered.
Web-scripting viruses come with the code integrated into the script of web-pages. You catch the computer virus when you visit the infected page.
Browser hijackers are pieces of malicious software, which alter the starting page of the browser without permission. As a result, a user is automatically directed to a scammer website as soon as he opens the browser.
Polymorphic viruses are one of the most dangerous types of computer virus software. They alter their malicious code with every new launch of an infected file. By doing so, they yank around antivirus programs. That is why polymorphic viruses are so hard to detect and to eliminate.
Multipartite viruses are incredibly versatile and dangerous. They affect both system and executable files. You won’t get rid of the virus by removing an affected file.
Macro viruses are created with the help of the macro language. Popular apps, such as MS Word, also use this language. The viruses are integrated with the code of these apps, so they are activated when the app is executed.
How to Recognize if Your Device is Infected?
Early detection of a computer virus is crucial. The earlier you take measures, the higher the chances for a positive outcome are. Fortunately, there are certain symptoms of a viral infection, which can help to detect a threat timely.
Suspicious pop-up ads. If you see pop-up windows with aggressive ads, especially those offering to install anything, never click on them. Instead, scan your PC for viruses.
Spam messages sent from your email or social media account. If you see any messages that were not addressed by you or your friends complain about spam coming from you, it’s time to scan your PC and change the password to the account.
A new homepage in your browser. If you open the browser and see an unfamiliar website instead of the usual starting page, chances are hijackers attacked you.
Severe speed drops. If your PC suddenly begins working much slower than before, it can be a symptom of a virus. It can turn out that scammers steal your traffic.
Incorrect functioning and errors. If you fail to open documents or run applications, the files can be destroyed by viruses
Unknown apps and programs installed without your privity. If you see shortcuts of the apps, which were never installed by you, or something is installed automatically, immediately scan your PC.
You are losing access to accounts, altering passwords. If you see a warning about a wrong password, trying to access your e-mail or social media account, chances are it was hacked.
How Do You Get Rid of a Computer Virus?
If you suspect to have a virus, you should take measures immediately. Don’t ignore the problem; otherwise, you may lose personal data, email accounts, important files stored on the hard drive, and so on. In severe cases, the only way to get rid of a virus is a complete disk formatting. To detect the type of the virus and remove you’ll need a good trusted antivirus program.
How to Protect Yourself Against Computer Viruses
Undoubtedly, a computer virus can bring a lot of troubles. It can damage your files and cause numerous errors and crushes. Moreover, it can cause severe financial losses. That is why strong antivirus protection is a must-have in modern circumstances.
First and foremost, you must have antivirus software. If you are not ready to invest in premium antiviruses, there are some free and budget-friendly options available. Of course, you need to be very cautious when choosing a free antivirus, as there are plenty of scammer and fake products, which don’t provide a sufficient level of protection. Moreover, some of them contain malware.
When it comes to business network protection, a premium antivirus product is a must. Don’t try to save on security. If hackers get access to your sensitive data, you can lose more than 50 dollars spent on an antivirus pack. Besides, you can lose all your data.
While having a good antivirus is crucial, you also need to take proper preventing measures. Here are some basic security tips for everyone:
Never click on suspicious links even if your friends send them. Social media accounts and emails are hacked more frequently than you can imagine. If you are not sure what it is, ask your friend. Double-check everything you receive in messengers.
The same is about e-mail attachments. If you don’t know what it is and why you received it, ask the sender or ignore it.
Close aggressive pop-up ads and never believe the fake warning about viruses detected. Instead, scan your PC with a trusted, familiar antivirus.
Try not to use macros in MS Word without need.
If you think that viruses are everywhere, chances are you are not mistaken. You can catch it at any moment. Computer viruses are ingenious: they are easy to find and hard to remove. Always keep in mind that prevention is the best treatment, and the only way to avoid viruses is by using high-quality antivirus software.