How Can Malicious Code Do Damage? How Can You Prevent It?

Malicious codes can damage your digital devices in various ways, such as corrupting files, disrupting system operations, infecting apps, changing system settings, and opening backdoors for cybercriminals to launch cyberattacks. They create vulnerabilities in the device system and network to expose it to a wide range of dangers. Attackers use these vulnerabilities and security holes to infiltrate your device and steal your personal information. Once they are inside your device, they can track your online activities, hijack your system using ransomware, and direct you to harmful websites that are set up by the attackers to manipulate users to steal money and sensitive business details. They can steal your identity and commit financial fraud in your name.

Written by R K Dutt
Published on September 19, 2025

In addition to this, scammers can do malicious activities in your name that can make you stuck with the state authorities. So, this blog provides you with a detailed account of how malicious code can do damage and how you can prevent the damage. So let’s get started!

What is a Malicious Code?

A malicious code is a program or web script that is designed to infect digital devices, networks, and company databases, to create backdoors, exploit security vulnerabilities, and launch deadly cyber attacks on individuals and organizations. There are different types of malicious code, and they are named after their design and purpose.

For example, we have ransomware, spyware, Trojan horses, botnets, cryptojackers, browser hijackers, adware, rootkits, keyloggers, phishing URLs, zero-day exploits, and the list goes on and on. These are all malicious codes that online attackers use to target a user to overtake, infiltrate, and steal device data and disrupt system operations. So, malicious codes are harmful programs or digital scripts that are used to do all types of malicious activities.

Detailed Descriptions of Different Types of Malicious Codes

1. Viruses

Viruses are self-replicating harmful programs that attach to files and other programs to spread when the file is run in the system. It attaches to the other files and programs to spread when you download and run them on your PC. They always use a host file to spread and infiltrate a network and system.

2. Worms

Worms are other malicious programs that do not need any attachments or external files to spread and infiltrate a network and endpoints. It works on its own to spread, clog down networks. Once it is inside a network, it multiplies at a lightning-fast speed using the network and can spread worldwide in hours. ILOVEYOU worm is a prominent example in this case.

3. Trojan Horses

Trojan horses are malware programs that look safe and useful, but when you download and install them on your device, they start behaving in a bad way. Once a Trojan is inside your PC, it does all types of malicious activities, such as stealing your sensitive data, opening backdoors, and exploiting internal vulnerabilities. It connects your device to a remote server and allows hackers to take control over everything. Hackers can easily steal your sensitive device data and use it to remove access and commit financial fraud in your name. Zeus is one of the most prominent examples of a powerful Trojan horse that cybercriminals have used and steal banking data from their target computers.

5. Spyware

Spyware is another malicious program that is designed to spy on users and track all their online activities. If it enters your system, then it can quietly monitor and keep an eye on every activity in the PC without you knowing anything. During its operation in your device, it can steal your login details and financial information, completely shattering your online privacy and security. Spyware runs silently in the background and watches everything you do, and passes this information to the hackers operating from a remote location.

6. Adware

Adware is a potentially unwanted program that sends unwanted ads, notifications, alerts, and pop-ups, crowding your PC screen and slowing system speed. As a result, it spoils your browsing experience and exposes you to unwanted ads and malicious URLs that can direct you to unsafe websites. These things can lead to privacy and security breaches. Down the line, you become more vulnerable to online threats like ransomware, identity theft, and system compromise.

7. Rootkits

Rootkits are other malicious codes that are designed to operate covertly and at a very low level in your device’s system. Most often they reside in the system kernel and critical files, making it more difficult to detect and remove them. They disable the security software and maintain strong control over the operating system. With the help of this control they hide the presence of malware and viruses to do malicious activities. Rootkits provide remote access to the cybercrooks, silently stealing your sensitive data and tracking your online activities.

8. Logic Bombs

Logic bombs are like time bombs in your system that sit quietly, wait for the right moment and when it is time and right conditions they explode. When logic bombs become activated on their specified time and situation, they inflict heavy damage. It can delete your important files, crash your system, and erase your work in seconds. You won’t be able to detect their presence on your PC using the basic security software. Staying unnoticed from your eyes, they slowly see their work through.

9. Bots & Botnets

Hackers use different types of methods and malicious codes such as phishing attacks, drive-by-downloads, exploiting system vulnerabilities and worms to infect your PC and turn it into a bot. These carry out this activity at a large scale, infecting millions of devices and turning them into bots. After this, they connect these bots to create a network,which is called botnet. When this is done they use the botnet to launch a large scale cyberattack in which they run spam campaigns, crypto mining, overwhelming targeted websites, disturbing internet infrastructure, and disturbing the state security.

10. Browser Hijackers

Browser hijackers are highly advanced malicious programs that are used to modify browser settings and track the online activities of the targeted users. When they take over your browsers they can redirect you to malicious sites and download more malicious codes on your device. With the help of hijackers, black hats can spy on your online activities and steal your sensitive credentials such as banking passwords, social media login, and email access. They can spoil your online experience by showing you unwanted ads.

11. Fileless Malware

Fileless malware is an invisible malicious code that sneaks into your device and runs directly in memory. It doesn’t leave any trace or file behind when it enters your computer. It makes it really difficult for a traditional security program to detect and take appropriate action to prevent the loss. If it is inside your device, then it will abuse your legitimate system tools and run damaging commands. Additionally, it will spread to the inside network and do all types of harmful activities. It steals your data, moves to other connected endpoints,s and creates backdoors in the network for further security breaches.

How Can You Prevent Malicious Codes?

Cybercriminals create new malicious code every day and use different methods to embed it in your PC. By the time you have a security patch for the latest malicious codes a new threat comes up and this cycle goes on endlessly. In such a situation, you cannot just sit idle and see your online security shattered and personal data lost to the hands of black hats. You have to stay alert and always one step ahead to protect your PC, privacy, and online security. If you are feeling helpless and confused in this regard, then don’t worry. Here are some effective safety measures that help you prevent malicious codes from infecting your device and stealing personal data:

Advanced Antivirus Software

You must equip your digital device with an advanced antivirus software to prevent malicious code. It can detect the lurking dangers at the very doorstep when they make advancements at the very outset. Antivirus software scans your device in real-time to find out the hidden malicious programs and remove them before they inflict any damage. When you visit an unsafe website that is compromised with the malware, it sends you advanced security alerts.

Whether it is the latest cyber threats or hidden malicious codes, antivirus software can protect you from a wide range of lurking dangers. Some security software comes with unique features that fine-tune system resources and remove unwanted programs with your permission to increase the overall device performance. Hence, antivirus software is the first line of defense against malicious codes and malware-free online browsing experience.

Use a VPN

VPN (Virtual Private Network) offers an advanced level of network privacy to the users by encrypting online traffic, internet connection, IP Address and user location from internet providers, third-parties, and surveillance authorities. It creates a secure and private channel to protect your online activities from network spies and state agencies. You can anonymously connect to the internet and do your activities without any fear of privacy breach or online tracking. If no one knows your whereabouts, then cybercriminals won’t be able to target you. This way, you can become more secure and protected from malicious code.

Use a Firewall

A firewall is another important internet security tool that examines your online network traffic to filter out unsafe data packets to prevent malicious codes from entering your PC. On the basis of online security, it decides what’s allowed in and what’s kept out. It monitors traffic flowing in and out of your device network to detect and block suspicious programs. It allows only trusted and safe data packets to protect your system from malicious codes and programs.

Don't Click Suspicious URLs

If you receive any email from an unknown sender and it contains any URL or download link don’t click it. Black hats use phishing attacks to target a user and direct them to an unsafe website tampered with the malicious codes. When you click on such suspicious URLs, malware enters your device and compromises all the data inside. So, avoid clicking suspicious URLs coming from unknown resources.

Keep Your System Up-to-Date

Outdated device programs and operating systems develop vulnerabilities that provide cybercriminals a backdoor to intrude on them. To fix these vulnerabilities you must download the latest updates as soon as they are made available. Software vendors upload new updates all the time to fix the system vulnerabilities, add new features and provide a better user experience. For better user experience and risk-free browsing experience it is important that you keep your system up-to-date.

Download From Trusted Sites

Don’t use any third party site or platform to download your files, apps and programs. They can come with malicious threats and malware infections. Use only official sites and trusted platforms to download your apps and programs. Check the URLs, emails or messages before you download anything using them. Black hats use URLs to infect your device with harmful programs. Using trusted sites can save you from big troubles and prevent malicious codes in your devices.

Safe Browsing Practices

When you are searching for something and visiting a website look for HTTPS before the link. S in the HTTPS stands for secure. Along with this you will see a lockpad that says connection is secure. These signs are strong indications that tell you that this site is secure and your data is end-to-end encrypted. They are indicators that the site you are visiting is following internet security protocols. You must avoid shady pop-ups, free offers, or unknown download prompts. It can lead you to virus infections and security breaches.

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How Can Malicious Code Do Damage? How Can You Prevent It?

What is a Malicious Code?