We all think we know what a computer virus is, but many people can not identify the different types of viruses, or how to protect their devices against them. To help bridge this knowledge gap we have created a three part series that covers the types of viruses, how they spread and how you can defend yourself from them.
let’s begin with the basics.
What Is A Computer Virus?
A computer virus is a program or peice of code which is loaded onto a computer without the users knowledge or consent. These malicious programs run against your wishes and can be extremely difficult to remove. Many viruses can also replicate and spread autonomously.
Now that you know what a computer virus is, here are the common types of viruses you may come across.
Common Types Of Computer Viruses
A Trojan Horse virus is a destructive program which disguises itself as another application. They do not replicate and spread autonomously, instead relying entirely on user interaction, such as opening an email attachment or running an infected file downloaded from the internet. A trojan can do a lot of damage once you activate it. This can include seeking ransoms to undo the vandalism done to your computer, steal your account information, or even download and install more malicious programs which may be additional trojans or adware.
A virus that avoids detection by antivirus software. Typically when an antivirus program is run, a stealth virus hides itself in it's memory, and uses various tricks to hide the changes it's made to the files.
This type of virus avoids detection by maintaining a copy of the original uninfected files while monitoring the systems activity. When a program tries to access data that's been altered, the virus redirects it to the uninfected data.
A good virus software program should be able to find a stealth virus regardless of its attempts to hide. By looking for evidence in the systems memory and common areas viruses are known to attack, a powerful virus software will protect your critical data.
A complicated computer virus designed to affect data types and functions. It is self encrypted and intended to avoid detection by scanners. It achieves this by replicating itself, creating usable, ever so slightly modified copies that aim to infect databases. It's time consuming, complex and costly to remove this type of virus.
A computer worm is a stand alone malware which replicates itself and spreads through computer networks. They can also be spread through email attachments or direct messages. Worms do not need to attach themselves to existing programs. Worms can modify, delete and create files all without the users knowledge. They can also steal data, install a backdoor, even allow hackers to gain control over your computer and it's system settings.
A virus that is found in infected spreadsheets, word documents and similar applications. Macros cause a series of actions to automatically run, usually when the application is opened, or when it is triggered. They spread through email attachments, moving quickly as infected documents are shared, Macros tend to be surprising and annoying, but relatively harmless compared to other viruses.
Bots automate processes that are usually done by a human. A typical use of a bot is to gather information. A bot can be used for good or malicious intent. An example of malicious intent would be a bot designed to infect a user and connect back to the central server. This server acts as a command and control (C&C) centre for an entire network of infected devices known as a botnet. Bots can log keystrokes, gather passwords, capture and analyze packets, gather financial information, launch DOS attacks, replay spam, and open backdoors on the infected host. Needless to say, bots can to do a lot of damage.
It is important to be informed of the potential threats your computer network can come into contact with. If you are handling very sensitive data, whether that be in the healthcare industry, a financial institution or any other organization that handles clients personal information, you can not afford to remain ignorant to these threats. As they say, knowledge is power.
Now that we have basic knowledge of common viruses and what they do, how could they spread to your computer? We have created a fun infographic, because we know how tedious this information can be to absorb. It is important that everyone on your team is aware of viruses and how you could become vulnerable to their attacks.