Virus
A computer virus is a malicious piece of computer code designed to spread from device to device. A subset of malware, these self-copying threats are usually designed to damage a device or steal data.
Think of a biological virus – the kind that makes you sick. It’s persistently nasty, keeps you from functioning normally, and often requires something powerful to get rid of it. A computer virus is very similar. Designed to replicate relentlessly, computer viruses infect your programs and files, alter the way your computer operates or stop it from working altogether.
Some computer viruses are programmed to harm your computer by damaging programs, deleting files, or reformatting the hard drive. Others simply replicate themselves or flood a network with traffic, making it impossible to perform any internet activity. Even less harmful computer viruses can significantly disrupt your system’s performance, sapping computer memory and causing frequent computer crashes.
Symptoms
Slow computer performance
Erratic computer behavior
Unexplained data loss
Frequent computer crashes
Trojan
A Trojan, or Trojan horse, is a type of malware that conceals its true content to fool a user into thinking it's a harmless file. Like the wooden horse used to sack Troy, the "payload" carried by a Trojan is unknown to the user, but it can act as a delivery vehicle for a variety of threats.
Types of Trojan
Backdoor Trojans - This type of Trojan allows hackers to remotely access and control a computer, often for the purpose of uploading, downloading, or executing files at will.
Exploit Trojans - These Trojans inject a machine with code deliberately designed to take advantage of a weakness inherent to a specific piece of software.
Rootkit Trojans - These Trojans are intended to prevent the discovery of malware already infecting a system so that it can affect maximum damage.
Banker Trojans - This type of Trojan specifically targets personal information used for banking and other online transactions
Distributed Denial of Service (DDoS) Trojans - These are programmed to execute DDoS attacks, where a network or machine is disabled by a flood of requests originating from many different sources.
Downloader Trojans - These are files written to download additional malware, often including more Trojans, onto a device.
Phishing
Phishing attacks are the practice of sending fraudulent communications that appear to come from a reputable source. It is usually done through email. The goal is to steal sensitive data like credit card and login information, or to install malware on the victim’s machine. Phishing is a common type of cyber attack that everyone should learn about in order to protect themselves.
Phishing starts with a fraudulent email or other communication that is designed to lure a victim. The message is made to look as though it comes from a trusted sender. If it fools the victim, he or she is coaxed into providing confidential information, often on a scam website. Sometimes malware is also downloaded onto the target’s computer.
Types of Phishing attacks
Deceptive phishingDeceptive phishing is the most common type of phishing. In this case, an attacker attempts to obtain confidential information from the victims. Attackers use the information to steal money or to launch other attacks. A fake email from a bank asking you to click a link and verify your account details is an example of deceptive phishing.
WhalingWhen attackers go after a “big fish” like a CEO, it’s called whaling. These attackers often spend considerable time profiling the target to find the opportune moment and means of stealing login credentials. Whaling is of particular concern because high-level executives are able to access a great deal of company information.
PharmingSimilar to phishing, pharming sends users to a fraudulent website that appears to be legitimate. However, in this case, victims do not even have to click a malicious link to be taken to the bogus site. Attackers can infect either the user’s computer or the website’s DNS server and redirect the user to a fake site even if the correct URL is typed in.
Malware
Malware is any type of software created to harm or exploit another piece of software or hardware. Malware is a collective term used to describe viruses, ransomware, spyware, Trojans, and any other type of code or software that’s built with malicious intent.
Malware can crack weak passwords, bore into systems, and spread through networks. Other types of malware can lock up important files, spam you with ads, or redirect you to malicious websites. Malware attacks can result in anything from data theft to the destruction of entire systems or devices.
Types Of Malware
Viruses
Trojans
Spyware
Worms
Ransomware
Adware
Scareware
Botnets
Rookits
Cryptominers
Logic Bombs
Malicious Code
Malicious code is unwanted files or programs that can cause harm to a computer or compromise data stored on a computer. Various classifications of malicious code include viruses, worms, and Trojan horses.
Types
Viruseshave the ability to damage or destroy files on a computer system and are spread by sharing an already infected removable media, opening malicious email attachments, and visiting malicious web pages. /p>
Worms are a type of virus that self-propagates from computer to computer. Its functionality is to use all of your computer’s resources, which can cause your computer to stop responding.
Trojan Horses are computer programs that are hiding a virus or a potentially damaging program. It is not uncommon that free software contains a Trojan horse making a user think they are using legitimate software, instead the program is performing malicious actions on your computer.
Malicious data files are non-executable files—such as a Microsoft Word document, an Adobe PDF, a ZIP file, or an image file—that exploits weaknesses in the software program used to open it. Attackers frequently use malicious data files to install malware on a victim’s system, commonly distributing the files via email, social media, and websites.
Hacking/Hackers
Hacking refers to activities that seek to compromise digital devices, such as computers, smartphones, tablets, and even entire networks. And while hacking might not always be for malicious purposes, nowadays most references to hacking, and hackers, characterize it/them as unlawful activity by cybercriminals—motivated by financial gain, protest, information gathering (spying), and even just for the “fun” of the challenge.
Hacking is typically technical in nature (like creating malvertising that deposits malware in a drive-by attack requiring no user interaction). But hackers can also use psychology to trick the user into clicking on a malicious attachment or providing personal data. These tactics are referred to as “social engineering.”
Many think that “hacker” refers to some self-taught whiz kid or rogue programmer skilled at modifying computer hardware or software so it can be used in ways outside the original developers' intent. But this is a narrow view that doesn't begin to encompass the wide range of reasons why someone turns to hacking.
How Hackers attack Networks?
Footprint analysis or Reconnaissance: Footprint analysis or Reconnaissance is the first step typically performed by a network hacker. In Footprint analysis or Reconnaissance, hacker gathers information about the target network. Footprint analysis or Reconnaissance is to map the addresses, devices, operating systems, application running in the target network.
Footprint analysis or Reconnaissance helps attacker to tailor an attack plan to exploit known vulnerabilities configuration errors in the target network.
Attackers use many information which are available in the internet like DNS lookups to find the name and IP address of the target network, WHOIS information to find the contact details name server names etc.
Spyware
Spyware is loosely defined as malicious software designed to enter your computer device, gather data about you, and forward it to a third-party without your consent. Spyware can also refer to legitimate software that monitors your data for commercial purposes like advertising. However, malicious spyware is explicitly used to profit from stolen data.
Whether legitimate or based in fraud, spyware’s surveillance activity leaves you open to data breaches and misuse of your private data. Spyware also affects network and device performance, slowing down daily user activities.
All spyware peeks into your data and all your computer activity — whether authorized or not. However, many trusted computer services and applications use “spyware-like” tracking tools. As such, the spyware definition is reserved mostly for malicious applications nowadays.
In short, spyware communicates personal, confidential information about you to an attacker.
Data compromised by spyware often includes collecting confidential info such as:
Login credentials — passwords and usernames, Account PINs, Credit card numbers, Monitored keyboard strokes, Tracked browsing habits, and Harvested email addresses
Adware
Adware is the one kind of malware (malicious software). Causes Pop-ups to take over your screen. Adware, meaning “advertising malware,” displays unwanted advertisements using intrusive and potentially dangerous methods. Adware can cause infinite pop-ups-which is ads constantly popping, Spying-Tracks your daily activities both online and off, Main-in-the-middle attacks- which is Adware like Super fish operate by redirecting all of your traffic through their system so they can display advertisements, but they do this even over what should be protected connections, Slowing down your device- Loading and running advertisements draws processing power away and slows down the devices performance, Eating up your data- Download a image, media or advertisements takes a high amount of your monthly mobile data.
Adware is unwanted software designed to throw advertisements up on your screen, most often within a web browser. Some security professionals view it as the forerunner of the modern-day PUP (potentially unwanted program). Typically, it uses an underhanded method to either disguise itself as legitimate, or piggyback on another program to trick you into installing it on your PC, tablet, or mobile device.
Adware generates revenue for its developer by automatically displaying online advertisements in the user interface of the software or on a screen that pops up in the user’s face during the installation process. And that’s when you start seeing dubious miracle weight loss programs, offers for get-rich-quick secrets, and bogus virus warnings that invite your click. Also, you might experience new tabs opening, a change in your home page, findings from a search engine you never heard of, or even a redirect to a NSFW website.
Mind you, it does happen that legitimate software applications do use online advertising, with ads that are typically bundled within the program and that display in ways the program developer specified. Adware is an altogether different kettle of rotten fish. You might download it without understanding its intent. Or it might land on your PC by means of legitimate software within which it’s secretly buried. Whatever the path, it all boils down to some program on your computer showing you advertisements that do not come from the websites you are visiting.
Once adware hijacks your device, it might carry out all sorts of unwanted tasks. The software's functions may be designed to analyze the location and which Internet sites you visit, and then present advertising pertinent to the types of goods or services featured there. While adware is more of a pesky nuisance than a harmful malware threat to your cybersecurity, if the adware authors sell your browsing behavior and information to third parties, they can even use it to target you with more advertisements customized to your viewing habits. And it doesn’t matter whether you are using Chrome, Firefox, or other browsers: It affects all of them.
Here are a few typical telltale signs that you have adware on your system:
Advertisements appear in places they shouldn’t be.
Your web browser’s homepage has mysteriously changed without your permission.
Web pages that you typically visit are not displaying properly.
Website links redirect to sites different from what you expected.
Your web browser slows to a crawl.
New toolbars, extensions, or plugins suddenly populate your browser.
Your Mac starts automatically installing unwanted software applications.
Your browser crashes.
