Is Your Computer Infected By Virus?

Although we have a good antivirus installed on our computer and we pay all the attention in the world to avoid falling into the clutches of viruses, there is always a certain probability of ending up infected by this type of software. There are viruses so subtle, and with such advanced techniques, that neither we are able to recognize them nor antivirus to detect them. At least until it's too late. What is usually common is that, in a short time, our PC begins to malfunction. And that's when we start to suspect that we have a virus.

There are a wide variety of different types of malware. Each of them has a purpose and acts in a specific way.

The signs of the viruses from before were very clear. For example, some opened and closed the CD reader, others made a ball appear bouncing across the screen, and others directly erased all the information on the hard drive and that's it. That when they did not force to write in a sector and they literally burned the hard disk.

However, now things have changed and viruses can become so subtle that it can take weeks or months for the slightest indication that our computer has a virus appears.

For this reason, either by carrying out a regular maintenance of the computer or by suspecting that we may be infected by malware, below we explain how to carry out a complete diagnosis of the PC to detect any possible unwanted threat.

Suspicions That My Computer Has A Virus

Depending on the type of virus, our computer may act in one way or another. It may not even do anything weird and it is much more difficult to suspect that we are infected.

Adware and Spyware

The adware and spyware are viruses designed to generate income for the hackers at the expense of our data and our personal information. Adware, on the one hand, focuses on displaying advertising all over the computer, as well as within the web browser, while spyware seeks to collect personal data (passwords, bank details, and everything else) and sends it remotely to the hacker. IT.

The main signs that our computer is infected by this type of malicious software are:

A lot of advertising appears on our computer. When we have the browser closed, banners appear on the desktop. And when we surf the Internet, the websites show many more ads and windows than normal.

Unknown extensions and task bars appear in the web browser.

Our firewall warns us that some unknown program wants to connect to the Internet.

Some browser features (such as automatic updates) are disabled.

We cannot enter the antivirus web pages.

We get more junk mail than usual.

The web browser opens without permission and loads webs randomly.

Fake antivirus, fake technical support or "rogueware"

Surely we have ever seen fake antivirus or fake tech support apps. These applications try to pretend to be an antivirus or a program to fix errors on our computer and tell us, lying, that we have hundreds or thousands of viruses or errors on our PC. When we try to solve them, it asks us to pay a license or enter our bank details. Everything, in the end, ends up in the hands of hackers.

One version of this type of threat is fake technical support. These generally arrive through malicious web pages created to deceive their visitors. These websites say that viruses or errors have been detected on our computer and ask us to call Microsoft technical support to solve the problem. During the call they will offer us remote control, install a program (a Trojan) and ask to make a transfer or pay money to correct the problem. These fake websites may even block our computer by putting the CPU at 100%, preventing us from closing them.

The signs that show an infection with this type of malware are:

·       Messages appear telling us that we have thousands of viruses and errors on our PC.

·       Our computer speaks suddenly. The websites usually have phrases that warn us of the problem.

·       The computer starts to run slow.

·       There are applications that try to access the Internet without permission.

·       The computer crashes or restarts frequently.

·       Opening programs like Google Chrome or watching videos becomes much slower, and with problems.

·       Many programs cannot be opened. Especially those related to security.

·       Antivirus and firewall disappear or are disabled.

Trojans

The Trojans with wider type of malware. A Trojan can do almost anything on your PC. The most common are RATs, those that seek to allow the hacker to connect remotely to our computer. When this malware infects us, the hacker has full control over our computer and can download files, steal passwords and bank details, and even install other viruses on the PC.

There are also other types of Trojans depending on the purpose of the hackers:

Backdoor: to enable back doors through which to communicate remotely with our PC.

Exploits: to exploit flaws and vulnerabilities in our computer.

Banking: exclusively focused on collecting and stealing bank details.

Rootkit: focuses on creating persistence. Sometimes it even takes the malware into the PC's BIOS.

Downloader: used to update the Trojan, send new versions and add-ons. The "dropper" variant is responsible for downloading other types of viruses and Trojans on our computer.

Normally, a Trojan usually has a specific function with a module that allows hackers, once the computer has been infected, to add functions to it through "plugins".

The symptoms that our computer has a Trojan are:

·       Our computer crashes or does strange things.

·       Some programs run without permission.

·       The computer is slow or takes a long time to start.

·       Strange applications and services try to connect to the Internet.

·       Some apps don't work. For example, Internet Explorer.

·       We get too much junk mail. Or emails with logins on websites where we have not entered.

·       The hard drive is constantly working.

·       Not many web pages work.

·       Some personal files disappear, or are modified.

·       Antivirus and firewall disappear. And they cannot be run or installed again.

·       Ransomware or extortion software

The ransomware is the most dangerous malware that can be found today. Normally this type of malware is usually undetectable by most antivirus and, when we realize that we are infected, it is too late.

The ransomware was born from the police virus. What this virus did was show us a screen in which they indicated that we had been caught doing illegal things on the Internet and asked us to pay a fine. All false. But it was just a screen that blocked our computer, but no files or anything was deleted.

However, today's ransomware acts differently. When they reach the computer, what they do is encrypt all of our personal data so that we cannot access it. We lose them completely. It also asks us to pay a ransom, in Bitcoin, which allows us to recover the private key to decrypt the data and recover it. Of course, it doesn't always work, and sometimes we lose money as well as data.

Signs of a ransomware infection are:

·       Our personal files have disappeared.

·       New files appear with strange names and extensions.

·       Text files appear on the desktop and in folders with instructions for recovering data.

·       The computer is locked with a screen with instructions to pay and unlock it.

·       A program tries to connect to the Internet, or download other components from the network.

How To Check Your Computer For A Virus?

If we experience any of the signs that we have seen in the previous points, we almost certainly have a virus. And since viruses today are very difficult to detect with the naked eye, we just have to trust our instincts.

If we have an antivirus installed, either Windows Defender or a good reliable antivirus, and the virus has not blocked it, we can use it to scan our computer for viruses. A complete scan of the PC will help us find the virus. Or if not, at least other signs that we are infected (such as other secondary viruses used by a Trojan).