What is Ransomware: How It Works, Types, and Prevention tips

In today’s digital age, where nearly every aspect of our personal and professional lives is connected to the internet, cybersecurity threats have become more sophisticated and dangerous. Ransomware stands out as one of the most disruptive and costly. Whether it’s a multinational corporation, a local hospital, or an individual user, no one is immune to the risk of having their systems locked or data stolen by cybercriminals demanding payment.

Ransomware attacks have evolved from simple scams to highly organized operations, often involving advanced encryption, double extortion tactics, and even customer support for victims willing to pay. With damages expected to surpass $30 billion globally by 2025, understanding how ransomware works and how to protect against it is not just a technical necessity—it’s a business and personal imperative.

In this blog, we’ll explore the mechanics of ransomware, its various forms, real-world examples, current trends, and, most importantly, how to defend against this growing cyber threat.

What is Ransomware?

Ransomware is malicious software (malware) designed to block access to a computer system or files until money is paid, hence the term “ransom.” These attacks are carried out by cybercriminals who typically demand payment in cryptocurrency, making the transactions more challenging to trace. Unlike other types of malware that might simply spy on or damage a system, ransomware directly extorts the victim by encrypting critical files or systems and threatening permanent data loss or public exposure unless the ransom is paid.

The first known ransomware attack occurred in 1989, known as the “AIDS Trojan.” Since then, ransomware has evolved significantly in sophistication and scale, affecting individuals, businesses, hospitals, governments, and critical infrastructure.

Ransomware Attacks: A Growing Cyber Threat

Ransomware attacks are now among the most financially damaging and disruptive cyberattacks in the world. They often shut down businesses for days or even weeks, causing extensive financial losses and reputational damage.

Recent Stats on Ransomware

• According to a 2024 report by Cybersecurity Ventures, global ransomware damages are expected to exceed $30 billion by the end of 2025.
• A 2025 Sophos survey revealed that 66% of organizations were hit by ransomware in the past year, with the average ransom payment exceeding $1.5 million.
• The healthcare sector remains one of the top targets, with 1 in 3 hospitals in the U.S. experiencing a ransomware-related service disruption in the last year.
• February 2025 saw a dramatic increase in ransomware incidents, with 956 reported victims globally, an 87% rise from January. The manufacturing sector was the most targeted, and the United States remained the primary focus of these attacks. Emerging ransomware groups such as Anubis and Linkc Pub contributed to this surge.

These statistics underscore the urgency of understanding and mitigating the threat of ransomware.

How Does Ransomware Work?

Ransomware typically operates in a multi-step process:

1. Infiltration: The malware enters the victim’s system, often via phishing emails, malicious links, or unsecured remote desktop protocols (RDP).
   
2. Execution: Once inside, the malware executes its payload, which may involve encrypting files, stealing data, or both.
   
3. Notification: A ransom note is displayed on the victim’s screen, demanding payment in exchange for a decryption key or to prevent data leaks.
   
4. Payment and (Sometimes) Decryption: Attackers may provide a decryption key if the ransom is paid. However, there’s no guarantee they will.

Types of Ransomware

Ransomware is malicious software that encrypts or locks your data, demanding payment (usually in cryptocurrency) to restore access. There are several types of ransomware, including:

Crypto Ransomware

• Encrypts files on a device, making them inaccessible without a decryption key.
  
• Example: WannaCry, CryptoLocker

Locker Ransomware

• Locks the user out of the device or operating system, preventing interaction.
  
• Typically does not encrypt files.
  
• Example: WinLocker

Scareware

• Displays fake warnings or alerts (e.g., claiming to be antivirus software) and demands payment.
  
• May or may not lock or encrypt data.

Doxware / Leakware

• Threatens to publish stolen sensitive data unless a ransom is paid.
  
• Combines elements of ransomware and data exfiltration.

Ransomware-as-a-Service (RaaS)

• A business model where cybercriminals rent out ransomware tools to others.
  
• Operators take a cut of any ransom payments.
  
• Example: REvil, DarkSide

How Ransomware Gets on Your Computer?

1. Phishing Emails

Phishing emails are one of the most common methods ransomware uses to infect computers. These emails often appear from legitimate sources, such as banks, delivery services, or even your employer. They typically contain a malicious attachment, like a Word document, a PDF, or a link to a fake website. The ransomware is downloaded and executed on the system when the user opens the attachment or clicks the link. These attacks rely heavily on social engineering to trick users into taking action.

2. Malicious Links and Ads (Malvertising)

Malicious advertisements, or malvertising, are another way ransomware can spread. Hackers embed malicious code in online ads that appear on legitimate websites. When a user clicks the ad, or sometimes even loads the page, ransomware can be downloaded in the background. This method often takes advantage of browser vulnerabilities or outdated plugins, especially for users without recent security patches.

3. Drive-by Downloads

Drive-by downloads occur when visiting a compromised or intentionally malicious website, causing ransomware to be downloaded automatically without any direct action from the user. These websites exploit vulnerabilities in browsers, browser extensions, or outdated software to install ransomware silently. Users may not even realize their system has been infected until it’s too late and their files are encrypted.

4. Remote Desktop Protocol (RDP) Attacks

Remote Desktop Protocol (RDP) allows remote access to a computer or server, but it becomes a significant vulnerability if it’s poorly secured. Cybercriminals scan the internet for RDP-enabled computers and try to gain access using weak or stolen login credentials. Once they’re in, they can manually install ransomware on the system. This method is commonly used in attacks against businesses, schools, and healthcare systems.

5. Exploiting Software Vulnerabilities

Ransomware often spreads by exploiting unpatched vulnerabilities in software, including operating systems and applications. When software developers release updates, they usually include security patches to fix known flaws. If users fail to update their systems, attackers can use known exploits to gain access. A notable example is the WannaCry ransomware attack, which exploited a Windows SMB protocol vulnerability to infect thousands of systems worldwide.

6. Infected or Pirated Software

Downloading pirated software, cracks, or keygens from untrusted websites is another dangerous path to infection. These programs function normally but often include hidden malware. When the user installs the software, the ransomware activates in the background. This method targets users looking for free versions of commercial software, who may not realize the hidden cost is much greater than the original price.

7. USB Drives and External Devices

Ransomware can also spread through infected USB drives or other removable media. If a device is plugged into a computer with autorun enabled, or if the user opens an infected file on the drive, the ransomware can install itself. This method is commonly used in targeted attacks, such as those against companies or government agencies, where physical access is possible.

How does AstrillVPN help in preventing ransomware incidents?

Using AstrillVPN can be supportive in reducing the risk of ransomware incidents, though it should not be seen as a complete solution. AstrillVPN helps protect against ransomware primarily by encrypting your internet traffic and masking your IP address, which makes it more difficult for cybercriminals to monitor your online activity or identify your device as a target. This is particularly valuable when using public Wi-Fi networks, where attackers often snoop on unencrypted data to deliver malware or redirect users to malicious websites.

AstrillVPN also helps prevent exposure to ransomware via malicious websites by offering features such as ad and tracker blocking and DNS leak protection, which can reduce the risk of accidentally visiting harmful domains that distribute malware. Astrill allows users to route traffic through secure servers in regions with stronger privacy laws, further limiting third-party tracking. However, it’s important to note that while a VPN can help reduce certain types of exposure, it does not block ransomware-laced email attachments, malicious software downloads, or vulnerabilities in outdated systems. Therefore, AstrillVPN is best used as part of a broader cybersecurity strategy that includes antivirus software, regular system updates, cautious online behavior, and frequent data backups.

Emerging Ransomware Trends

Double Extortion Attacks

A significant shift in ransomware tactics is the rise of double extortion. In these attacks, cybercriminals encrypt a victim’s files and steal sensitive data. If the victim refuses to pay the ransom, the attackers threaten to leak or sell the stolen information online. This approach adds additional pressure, especially on businesses and organizations that store confidential or regulated data, such as healthcare providers, law firms, and financial institutions.

Ransomware-as-a-Service (RaaS)

The growing use of ransomware-as-a-service has also transformed the ransomware landscape. In this model, skilled developers create sophisticated ransomware tools and lease them to less experienced criminals, who then carry out attacks. This division of labor has significantly increased the number of ransomware incidents worldwide. It also makes attribution more difficult, as many groups use the same malware under different names.

Targeted and Customized Attacks

Attackers are moving away from mass distribution and focusing instead on highly targeted attacks. These often involve extensive research on the victim before deployment. Cybercriminals identify valuable assets, exploit known vulnerabilities, and time their attacks for maximum disruption, such as during weekends or holidays when IT staff may be unavailable. High-value targets now include critical infrastructure, hospitals, government agencies, and large enterprises.

Encryption-less Extortion

Another emerging trend is encryption-less ransomware, where attackers skip file encryption entirely and focus solely on data theft and blackmail. These attacks are faster to execute and harder to detect, as they don’t rely on typical ransomware behaviors like mass file encryption. Victims may not realize they’ve been compromised until they receive a ransom demand to release their stolen data.

Advanced Techniques and Zero-Day Exploits

Some ransomware groups are adopting more sophisticated techniques, including the use of zero-day exploits—vulnerabilities that are unknown to software vendors. By exploiting these flaws before a patch is released, attackers gain access to systems with little or no resistance. Advanced persistent threats (APTs) may even lurk in a system for weeks or months, collecting data and waiting for the right moment to deploy ransomware.

Ransomware Attack Examples

WannaCry

WannaCry is one of the most notorious ransomware attacks in history. It emerged in 2017 and exploited a vulnerability in Microsoft Windows, spreading rapidly across networks in over 150 countries. The attack crippled hospitals, transportation systems, and businesses, particularly affecting the UK’s National Health Service. WannaCry highlighted the dangers of unpatched software and was a wake-up call for cybersecurity globally.

Ryuk

Ryuk is a ransomware strain known for targeting large organizations, especially in healthcare, education, and government sectors. It often enters networks via phishing emails or exploiting weak Remote Desktop Protocol (RDP) credentials. Ryuk is notorious for demanding high ransom payments and causing major operational disruptions. It has been linked to several high-profile attacks resulting in millions of dollars in damages.

Conti

Conti was one of the most aggressive ransomware groups operating under the ransomware-as-a-service model. Its operators combined fast-moving attacks with double extortion, threatening to publish stolen data if victims didn’t pay. Conti was responsible for attacks on critical infrastructure, including emergency services and government networks. Though officially disbanded in 2022, its tactics and code have influenced many active ransomware groups today.

LockBit

LockBit is a highly active ransomware strain known for its speed and efficiency. It uses advanced encryption techniques and often spreads quickly across corporate networks. LockBit attacks are carefully targeted, and the group offers “support services” to help victims pay ransoms, making the process feel disturbingly professional. LockBit continues to evolve, releasing updated versions like LockBit 3.0 to avoid detection and maximize impact.

BlackCat (ALPHV)

BlackCat, also known as ALPHV, represents a new generation of ransomware. It is written in Rust, a modern programming language that offers flexibility and resistance to reverse engineering. BlackCat is highly customizable and used in attacks against large enterprises and critical infrastructure. It supports multiple attack methods, including double extortion, and is part of the trend toward highly technical and modular ransomware.

Can Ransomware Infect Mobile Devices?

Yes, ransomware can infect mobile devices, including Android and iOS platforms. While mobile ransomware is less common than desktop variants, it is a growing threat as smartphones hold vast amounts of personal and sensitive data. On Android devices, ransomware spreads through malicious apps downloaded from third-party sources or phishing messages with infected links or attachments. Once installed, the malware can lock the device or encrypt files, demanding payment to restore access.

iOS devices are more secure due to Apple’s strict app review process and a tightly controlled ecosystem. However, they are not entirely immune. Jailbroken iPhones, which bypass Apple’s security restrictions, are particularly vulnerable. In rare cases, attackers have exploited iCloud accounts or used configuration profiles to lock devices and hold them for ransom. While mobile ransomware is still evolving, the increasing reliance on smartphones for personal and professional tasks makes it a target worth defending against.

How to Prevent Ransomware Attacks?

Keep Software Up to Date

One of the most effective ways to prevent ransomware attacks is to regularly update your operating system, apps, and security software. Many ransomware attacks exploit known vulnerabilities in outdated software. Applying patches and updates as soon as they become available helps close these security gaps before attackers can exploit them.

Avoid Suspicious Links and Attachments

Phishing remains a primary method for delivering ransomware. Users should be cautious when opening emails, especially those from unknown senders. Avoid clicking on suspicious links or downloading attachments without verifying the source. Legitimate companies rarely ask for sensitive information via email; any unexpected message should be treated with skepticism.

Use Strong Passwords and Enable Multi-Factor Authentication

Weak or reused passwords make accessing your accounts and systems easy for cybercriminals. Always use complex, unique passwords and enable multi-factor authentication (MFA) wherever possible. MFA adds an extra layer of protection by requiring a second verification form, such as a code sent to your phone, making unauthorized access more difficult.

Install and Maintain Reliable Security Software

Installing trusted antivirus or anti-malware software on your devices can help detect and block ransomware before it causes harm. Many security solutions also include features like real-time monitoring and email filtering, which help prevent ransomware from reaching your system in the first place.

Regularly Back Up Your Data

Frequent data backups are essential in mitigating the damage of a ransomware attack. Store backups in a secure, offline location, such as an external hard drive or a cloud service with version history. In the event of an attack, you can restore your data without paying the ransom. Testing your backups periodically is also essential to ensure they are working correctly.

Limit User Privileges and Disable Macros

Limiting administrative access to only those who need it reduces the risk of ransomware spreading across a network. Users should operate with the least privilege necessary for their roles. Additionally, disabling macros in Microsoft Office documents can prevent ransomware from executing malicious scripts embedded in files often delivered via phishing.

Major Ransomware Incidents in Recent Times

CDK Global – June 2024

In June 2024, CDK Global, a provider of IT solutions for car dealerships, suffered a ransomware attack attributed to the BlackSuit group. The attack disrupted services for thousands of dealerships across the U.S. and Canada. CDK paid a $25 million ransom, and while most services were restored by July 4, the incident led to financial losses exceeding $600 million and multiple lawsuits.

Victoria’s Secret – May 2024

Victoria’s Secret experienced a significant cybersecurity breach in May 2024, which temporarily shut down its U.S. website and corporate systems. The breach delayed the release of its first-quarter earnings report and affected in-store services. While payment data was not compromised, the incident underscored the growing threat to retailers. 

Kadokawa and Niconico – June 2024

The BlackSuit ransomware group targeted Japanese companies Kadokawa and Niconico in June 2024. The attack resulted in the theft of 1.5 terabytes of data, including personal information of over 250,000 users. Despite efforts to restore services, the platforms remained offline for nearly two months.

Panera Bread – March 2024

In March 2024, Panera Bread suffered a ransomware attack that disrupted its IT systems, including online ordering and payment services, across over 2,000 locations. The company later disclosed that employee data had been stolen during the incident.

LockBit Attacks – May and June 2024

The LockBit ransomware group was responsible for several high-profile attacks in 2024. In May, it targeted Canadian retailer London Drugs, demanding a $25 million ransom and threatening to release data. It attacked the University Hospital Center in Zagreb, Croatia, in June, causing significant operational disruptions. 

Clop Ransomware Group – February 2025

The Clop group emerged as a significant threat in early 2025, with 332 reported victims in February. Clop’s activities have been linked to exploiting vulnerabilities in widely used software, highlighting the importance of timely patching and system updates. 

These incidents and trends underscore ransomware threats’ evolving and persistent nature across various sectors. Organizations are urged to implement robust cybersecurity measures, including regular system updates, employee training, and incident response planning, to mitigate the risks associated with such attacks.

Conclusion

Ransomware has transformed from a niche cyber threat into a global epidemic, impacting businesses, governments, and individuals across every sector. Its devastating effects, from encrypted data and halted operations to financial loss and reputational damage, underscore the critical need for robust cybersecurity strategies.

While no system is entirely immune, proactive steps such as regular backups, system updates, employee training, and endpoint security can significantly reduce your risk. Understanding how ransomware operates is the first step toward defense. By staying informed and vigilant, you can outmaneuver the attackers and protect what matters most: your data, your business, and your peace of mind. 

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