Identifying Malware

What is Malware?

Malware is short for "malicious software," and it refers to any software designed to harm, exploit, or otherwise compromise the performance and security of a computer, network, or device. Malware is a broad term that encompasses a variety of harmful software programs that can disrupt your system’s normal functioning, steal data, or give unauthorized access to malicious actors.

Malware can target individuals, businesses, and governments alike, causing damage ranging from a minor inconvenience to large-scale data breaches and financial loss. It’s important to understand the different types of malware, how they spread, and how to protect yourself from infection.


Types of Malware

Malware comes in many different forms, each with its own objectives and methods of attack. Below are some of the most common types:

1. Viruses

  • A virus is a type of malware that attaches itself to a legitimate program or file. When the infected file or program is executed, the virus activates and can spread to other files, programs, or even other computers.
  • Purpose: Viruses can corrupt or delete files, steal information, or even render a computer system inoperable. Some viruses are designed to replicate and spread, making them dangerous to an entire network.
  • Example: The ILOVEYOU virus, one of the most infamous, spread through email attachments and caused billions in damages globally.

2. Worms

  • A worm is a self-replicating type of malware that spreads across networks without needing to attach itself to a file or program, unlike a virus.
  • Purpose: Worms often exploit vulnerabilities in network protocols to propagate, and their primary purpose is to infect as many devices as possible. They can lead to a variety of problems such as system crashes or the creation of backdoors for further attacks.
  • Example: The Conficker worm, which infected millions of computers in 2008, was one of the most notorious worms.

3. Trojans

  • A Trojan horse (or simply a Trojan) disguises itself as legitimate software but actually contains malicious code. Users are tricked into downloading or executing the Trojan, believing it to be safe.
  • Purpose: Trojans can give hackers unauthorized access to a victim’s system, steal sensitive information, install other malware, or disrupt system functionality.
  • Example: The Zeus Trojan is known for stealing banking information and login credentials.

4. Ransomware

  • Ransomware is a type of malware that encrypts the victim's files or locks them out of their system and demands a ransom payment to restore access.
  • Purpose: The attacker demands payment, usually in cryptocurrency, in exchange for decrypting the victim’s files or unlocking the system.
  • Example: WannaCry and NotPetya are well-known ransomware strains that caused widespread damage.

5. Spyware

  • Spyware is designed to secretly monitor a user’s activity and collect personal or sensitive information, often without the user’s consent or knowledge.
  • Purpose: Spyware can record keystrokes, track browsing habits, access personal files, or monitor login credentials. Some types of spyware may also display unwanted ads (adware).
  • Example: CoolWebSearch is a notorious spyware that altered web browser settings and redirected users to unwanted websites.

6. Adware

  • Adware is a type of software that automatically displays or downloads advertising material when a user is online. While adware itself isn’t always malicious, it can lead to unwanted pop-up ads, slow system performance, or be used to deliver malware.
  • Purpose: It collects user data to serve targeted ads, which may compromise privacy and contribute to the spread of other malicious software.
  • Example: Fireball adware redirects users to phishing websites to steal personal information.

7. Rootkits

  • Rootkits are a type of malware designed to hide or obscure the existence of other malicious software. A rootkit allows an attacker to maintain privileged access to a system without being detected.
  • Purpose: Rootkits are used to hide the presence of malware and create backdoors for ongoing access to a compromised system. They can be very difficult to detect because they are designed to remain hidden.
  • Example: The Sony BMG rootkit scandal in 2005 involved a rootkit being secretly installed on users’ computers through music CDs, compromising the system’s security.

8. Keyloggers

  • Keyloggers are tools that record every keystroke typed on a computer or mobile device. This includes everything from login credentials to personal messages and credit card numbers.
  • Purpose: Keyloggers are often used for identity theft, fraud, and spying on users. They can be delivered via Trojans or other malware types.
  • Example: A software-based keylogger could record sensitive information typed into online banking forms or login pages.

9. Botnets

  • A botnet is a network of infected devices (computers, smartphones, IoT devices) controlled by a single attacker, known as a "bot herder."
  • Purpose: Botnets are used to launch Distributed Denial-of-Service (DDoS) attacks, send spam emails, or steal data. Infected devices may also be used for mining cryptocurrency or other malicious activities without the user’s knowledge.
  • Example: The Mirai botnet infected thousands of IoT devices, which were used to launch one of the largest DDoS attacks in history.

10. Fileless Malware

  • Fileless malware does not rely on traditional files to infect a system. Instead, it exploits vulnerabilities in legitimate programs (like browsers or system tools) to run malicious code in the computer’s memory.
  • Purpose: Fileless malware is difficult to detect because it leaves no trace on the file system. It can be used to steal data, install other malware, or create backdoors.
  • Example: PowerShell-based attacks are a common example of fileless malware that executes commands using legitimate system tools to infect a machine.

How Malware Spreads

Malware can spread in several ways, depending on the type of attack:

  1. Email Attachments: Many types of malware, especially viruses, Trojans, and ransomware, are distributed through email attachments or malicious links. These attachments often appear to come from trusted sources, tricking users into downloading or opening them.

  2. Malicious Websites (Drive-By Downloads): Just visiting a compromised or malicious website can infect your computer with malware. These websites automatically download malicious code to your device without your knowledge or consent.

  3. Software Vulnerabilities: Malware can exploit vulnerabilities in software or operating systems. If you don’t update your software regularly, attackers may be able to install malware by taking advantage of known security flaws.

  4. Untrusted Downloads and Peer-to-Peer Networks: Downloading files, software, or media from untrusted sources, such as file-sharing networks or sketchy websites, can lead to malware infection.

  5. USB Drives and External Devices: Malware can also be spread through USB drives or other removable media. If an infected USB drive is plugged into a system, the malware may automatically execute.

  6. Social Engineering: Malware creators may use social engineering tactics to deceive users into installing malware. This includes fake software updates, deceptive pop-ups, and misleading download links.

How to Protect Yourself from Malware

  1. Keep Software Updated: Regularly update your operating system, browsers, and all installed software. Most updates include security patches that close vulnerabilities that malware can exploit.

  2. Use Antivirus Software: Install and maintain antivirus software to detect and block malware. Make sure it’s set to update automatically to keep up with the latest threats, Windows Defender comes by default on all Windows Operating Systems

  3. Avoid Clicking on Suspicious Links: Never click on suspicious email links or attachments. Be cautious of unsolicited emails from unknown senders, and avoid downloading attachments or clicking links in emails from untrusted sources.

  4. Use Strong, Unique Passwords: Using strong passwords for all accounts reduces the risk of malware spreading through compromised credentials. Consider using a password manager to keep track of your passwords securely.

  5. Back Up Your Data: Regularly back up important files to an external drive or cloud storage. If malware, such as ransomware, infects your system, having backups means you can restore your data without paying a ransom.

  6. Be Cautious with USB Devices: Be careful when inserting external devices like USB drives into your computer. Always scan external devices for malware before opening files.

  7. Educate Yourself and Others: Awareness is a powerful tool in preventing malware infections. Stay informed about current malware threats and educate others in your organization or family about safe online practices.

What to Do If You’re Infected by Malware

If you believe your computer or device is infected with malware, take immediate action:

  1. Disconnect from the Internet: Disconnect your device from the internet to prevent the malware from spreading or communicating with its command server.

  2. Run a Full Antivirus Scan: Use your antivirus software to run a full scan of your system. If the antivirus detects malware, follow the instructions to remove or quarantine it.

  3. Update and Patch Your Software: After cleaning your device, ensure that all your software and operating systems are fully updated to close any security holes the malware might have exploited.

  4. Change Passwords: If malware is designed to steal login credentials (like keyloggers or Trojans), change your passwords after removing the malware. Be sure to update passwords for important accounts, such as banking and email.

  5. Restore from Backups: If the malware has caused damage or data loss, restore your files from backups. Be sure the backups are clean and free from malware.

  6. Seek Professional Help: If you’re unable to remove the malware or your system is significantly impacted, consider seeking help from a professional IT support team or cybersecurity expert.

Powered by Zendesk