What is Malware?

Malware is software that can cause potential damage to your computer services and network. It stands for "Malicious Software" and is designed to disrupt the target's computer. Malware gets installed in the target system by unauthorized access, executable code, scripts, or software.

Malware can be in the form of a computer virus, trojan horse, worms, spyware, adware, ransomware, and scareware to name a few. Computers are protected against malware by preventing malware from gaining access to computers. This is often done by using antivirus, firewall, and similar protection software.

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Why are malware created?

The highest form of malware available in the market is Trojan Horses followed by computer viruses. Other malware such as worms, spyware, backdoor and adware follows its popularity. The very first form of the worm was created as an experiment. However, with the spread of Internet different forms of malware are created in large scale.

The intention behind malware are:

• To employ denial of Service attacks. This can bring the complete service down.
• To Extort money by ransomware where the target may require paying money to remove the ransomware.
• To carry out identity theft.
• To carry an Online banking fraud.
• To bring a bad reputation to an individual or company or service.
• To add spyware to track user data and behavior.
• To retrieve confidential information from government websites.
• To disrupt services by deleting files, folders or altering the computer default behavior.
• To use infected computer to send email spam.

While the above is a few intentions behind creating malware, some hackers create them as an experiment or prank.

Types of malware

Malware is a broader term and can be categorized into multiple types. As the cyberspace keeps expanding, there are newer types of malware being added.

The different types of malware are:

• Trojan Horse: Trojan or Trojan Horse is one of the most widely spread and dangerous malware. This disguises as a legitimate program and enters your computer. Once the trojan has gained access to your computer, it can steal data stored in your system. This can spread through emails or via the infected website.
  
  One of the most common trojans is the one which acts as antivirus software and gives a pop-up claiming your computer is infected. This would instruct the victim to clean the computer. The moment the victim clicks this software, trojan gains access to the computer.
  
  Trojans are so popular because they are easy to code and are also easy to spread by tricking the end user. There are millions of Trojans created every month and anti-malware would not have signatures for each of these.
• Viruses: Virus is a common term used by many to refer to all kinds of malware. However, not all malware are viruses. The number of viruses is lesser than trojans. A virus modifies a legitimate file and gets executed every time the file is executed by the victim.
  
  The virus would infect a legitimate program and hence is difficult to be cleaned up. Antivirus would clean this by either deleting the file or will quarantine it.
• Worms: Worms are similar to a virus but can self-replicate and spread to infect other computers. Worms have been around even before viruses and were first spread over emails. Unlike trojans and viruses, worms do not require end-user help to spread. The rate at which worms can spread makes it more dangerous.
• Spyware: Spyware would secretly log user activity without permission and send traces to the hacker. While this can be used to track activities of the user, it can also be used to log keystrokes and gain access to confidential information.
  
  Spywares are simpler to remove. You need to only uninstall or remove the spyware program. However, the existence of spyware indicates that there is an inherent flaw in computer security which must be considered and fixed at the earliest.
• Adware: Adware is a kind of malware where a program displays advertisement on your screen. This can monitor a user's online behavior. This can be in the form of popup and piggybacks itself to get installed on the user's computer. From here it displays advertisements whenever the user is online.
  
  Spyware and Adware are less malicious as compared to worms, trojans, and viruses.
• Ransomware: This is a type of malware, which might lock you out of your device or encrypt files to force you to pay a ransom. In most cases, ransomware first watches how much ransom the victim can afford. A good way to prevent this is by keeping an offline copy of important files. These payments are usually accepted in the form of cryptocurrencies which are hard to trace.
• Rootkit: Rootkit provides the attacker with administrative privileges over the victim's computer. This usually remains hidden and undetected from other software and the Operating system. With root access, it can cause potential damage and trace confidential information.
• Keylogger: A keylogger as the name suggest, records the victim's keystrokes. This information is gathered and sent to the attacker. This is a technique where sensitive information such as username, password, credit card details can be captured.
• Scareware: Scareware is a type of malware which is driven through social engineering. This creates anxiety, stress amongst victims and persuades them to buy unwanted software. These are usually shown as a virus threat and persuades the user to buy a fake antivirus.
• Botnet: Botnet consists of a series of internet-connected devices which can run one or more bots. This is used to perform Distributed Denial of Service (DDoS attack, send spam, steal data and intrude into target devices.
• Cryptojacking: This is malicious crypto mining. Also referred to as drive-by crypto mining is installed by a trojan. This lets the attacker take access and mine cryptocurrencies without the victim's knowledge. Once mined, the attacker will transfer the coins to their account.
• Exploits and malvertising: Malvertising refers to online advertising being used to spread malware. The malicious advertisement is injected into a legitimate website. Such scripts exploit any existing computer vulnerability and intrude into the victim's device.

Malware symptoms

Every category of malware may act differently and can spread or infect at a different rate. However, in most cases, all malware have few common symptoms and they are:

• Unusual slowness of the computer
• Increased CPU usage
• Unknown programs or services being displayed on computer's task manager
• Slowness in browser
• Issues while connecting to the network
• Random internet issues
• Screen freezing
• Computer crashing
• Modified or deleted files and directories
• Strange programs, desktops icons appearing on the computer
• Emails being sent without your knowledge
• Applications turning on or off, or reconfiguring automatically
• Applications taking long time to start
• Sudden popups and blue screens
• Change in the look and feel of screen and icons

If you experience one or more of the symptoms above, you may want to diagnose your computer for malware.

Malware Prevention

Finding malware and removing can be tedious at times, especially when you don't have much information about it. There are a few basic precautions you can take to prevent malware from entering your computer.

A few of the basic malware prevention tips are:

• Install a good anti-malware solution which can prevent trojan horse, virus, worms, spyware, and adware. Select an anti-malware which can regularly scan, quarantine and remove multiple types of malware.
• Use a Firewall to restrict and monitor incoming traffic.
• Install licensed software from official websites.
• Apply security patches and keep software, applications, plugins and Operating system up to date with the latest security updates.
• Avoid downloading files from unknown websites or attachments from unknown senders.
• Avoid clicking sudden popups which appear while browsing the Internet.
• Double check the URL before clicking. Do not click suspicious URLs or email links.
• Avoid installing software provided over online chats.
• Keep anti-malware solutions up to date.
• Use Intrusion Detection System (IDS) or Intrusion Prevention System (IPS) over the network.

Removal of Malware

Your computer can be infected with a malware through different sources. However, the topmost reasons are through emails and the Internet. Malware is often discussed to be prevalent on computers and laptops, but smartphones and tablets are equally susceptible to malware.

If you suspect malware on your smart devices, remove them immediately. Below are a few tips you can follow to remove malware.

• Install an anti-malware (or anti-virus) program. Scan your device(s) and clean the infected files.
• Change your computer or smartphone password regularly. You may also want to change passwords cached in your browser such as online banking, shopping sites, emails, and etc.
• If you're suspected of having a malware on your phone, you may factory reset your smartphone or tablet.
• Clean browser cache regularly.
• If any specific software is infected, uninstall and re-install it.
• If you have difficult time removing malware on your computer, format and reinstall the OS.
• Always have a anti-virus and firewall installed on your machine to prevent malware from entering your system.