Types of Ransomware

Published on: September 29, 2025

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15 min read

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For German Version

Ransomware is a type of malicious software designed to hold victims' data or systems hostage by encrypting files or locking devices for payment. It is a specialized form of malware specifically focused on extortion via data hostage-taking. The payment is asked usually in cryptocurrency to restore the blocked data. How the ransomware spreads, what they target, and how they operate mostly let experts categorize which type they are. Infection methods can be common with other malware types such as phishing, exploiting vulnerabilities, malicious downloads, and stolen credentials. Everyday malware may aim to steal or destroy data silently, and this quality makes them different then ransomware, as payment is demanded from the target with a threat.

Ransomware comes with significant damage more than just some amount of payment to the attackers. Data loss, unavailability or downtime, reputational damage, the costs are a part of the possible damage. Target range is from small initiatives and startups to healthcare, finance, automotive industries, and government sectors. Lessons from past attacks shows us that paying ransom is risky and data recovery may not be a guaranteed result. A layered, strong and proactive cybersecurity defense is essential.

Attacks using ransomware can take many different forms and vary widely in scale. The attack vector plays a significant role in the kinds of ransomware that are employed. It is always vital to take into account what is at risk or which information could potentially be released or erased in order to determine the magnitude and scope of the attack. The severity of an attack can be considerably decreased, irrespective of the form of ransomware, by properly using security software and storing up data beforehand.

Attack methods benefit from a combination of elements like data exfiltration for leakware, or social engineering for scam-based scareware. Distributed denial-of-service ransomware is also another method inspired from. The main versions of ransomware include crypto ransomware, leakware (Doxware or Extortionware), locker ransomware, DDoS ransomware, scareware and Ransomware as a Service (RaaS). Some notable ransomware cases and examples include Ryuk, WannaCry, CDK Global, Bad Rabbit, Maze, REvil. These types and examples of ransomware attacks are going to be mentioned in more detail in this article as well as the below topics;

• Crypto Ransomware (Encryptors)

• Locker Ransomware

• Scareware

• Leakware (Doxware / Extortionware)

• Ransomware-as-a-Service (RaaS)

• Fileless Ransomware

• Mobile Ransomware

• Which Type of Ransomware Is the Most Dangerous?

• What are the Most Common Ransomware Variants?

• Is Ransomware a Type of Malware or a Virus?

• How does Ransomware-as-a-Service (RaaS) Change the Threat Landscape?

• What Makes Fileless Ransomware Difficult to Detect?

• Can you Prevent Ransomware Attacks?

• What are the Top Ransomware Attacks?

• What is an Example of a Crypto Ransomware Attack?

• Is Ransomware a Trojan?

Crypto Ransomware (Encryptors)

Crypto ransomware is the most common form. It infects the victim’s system, executes encryption on files by using strong and complex cryptographic algorithms. Victims cannot access their data without the decryption key. The goal is to extort money from victims by holding their personal or company sensitive data hostage. Important data is out of access and there is financial loss of the ransom in case of ransom payment. There is a potential for data loss if backups are missing or corrupted, and the system now is more vulnerable to future attacks due to system information exposure. Examples include CryptoLocker, WannaCry, Cerber, Bad Rabbit, and Ryuk. CryptoLocker was a notorious ransomware active between 2013 and 2014. WannaCry is also a well-known example of crypto ransomware that spread globally in 2017.

Locker Ransomware

Locker ransomware locks the victim out of their device or system. The original owner, the user, can't get into their own system or device. Files in this case don't have to be encrypted. The objective is to extort money by denying access to the device rather than encrypting files. The attacker gets in through vectors like phishing or exploit kits, it locks the user’s system with system settings alternation or displaying a fake lock screen. The risks are complete loss of access to the system, operational disruption, potential data loss because of the inability to use the system. Variants are those which alter the Master Boot Record (MBR) or display fake law enforcement warnings to trick users into paying. Petya and Locky ransomware attacks are examples for locker ransomware. The Reveton malware locked screens and displayed fake messages from the FBI, and it is a classic example of locker ransomware.

Scareware

Scareware is malicious software designed to trick users into believing their system is infected or compromised. Scareware does not encrypt or lock files but it uses fake virus alerts to extort money for useless "removal" services. It generates misleading notifications or pop-ups warning of threats and urges users to purchase fake antivirus software or pay to fix non-existent problems. The main goal is to extort money or install other malware by scaring the victim. The risks are financial loss, installation of additional malware, system performance degradation. Fake antivirus alerts falsely claiming infections to induce panic purchases. Rogue antivirus programs like Antivirus 2009 were a common form of scareware that used aggressive pop-ups to trick users.

Leakware (Doxware / Extortionware)

Leakware, or alternatively called Doxware or Extortionware, steals sensitive data before encrypting files. The victim later is threatened with their stolen sensitive data to go public in case of no ransom payment. The Leakware method aims to put pressure on victims and make them pay if they don't want their data leaked to the public. This is extortion through blackmail with stolen sensitive personal data. There are data breach consequences, financial loss, and reputational damage. There may be legal and regulatory penalties, especially under laws like GDPR. There have been attacks where stolen corporate data is threatened to be leaked on the dark web if ransoms are unmet. Notable cases are REvil and Maze ransomware.

Ransomware-as-a-Service (RaaS)

Ransomware as a Service (RaaS) is a business model that aims to share ransom profits. Ransomware developers hire their malware to another party who carries out attacks and distributes ransomware to victims. In Raas, developers provide the ransomware infrastructure and collect a percentage of ransom payment in return.The objective is to commoditize ransomware, expand the attack reach and profitability. The risks for victims are increased ransomware volume, and widespread attacks. This model of ransomware spread also excites non-expert attack planners and turns up to an easier entry for them. DarkSide ransomware was distributed via RaaS platforms. The DarkSide group operated a successful RaaS model, and they were responsible for the Colonial Pipeline attack. Cerber and REvil are also common RaaS examples.

Fileless Ransomware

Fileless ransomware attacks do not rely on files being written to disk but operate in memory or use legitimate system tools to execute attacks. It exploits vulnerabilities to inject malicious code into legitimate processes. This also means to avoid traditional detection methods. The objective of the fileless ransomware is to bypass the antivirus detection and stick around longer for a better probability of ransom demand. It is harder to detect and remove, and it has a potential to cause widespread damage. These attacks leverage PowerShell or Windows Management Instrumentation (WMI) to execute ransomware payloads. The Powerliks malware is an example of a fileless attack that used PowerShell scripts to execute its malicious payload without writing a file to the disk.

Mobile Ransomware

Mobile ransomware targets smartphones and tablets to lock devices or encrypt mobile data. It is delivered via malicious apps or exploit kits, and it locks device screens or encrypts files and demands ransom. The objective is to extort money through mobile devices’ increasing data value. Loss of mobile access, financial theft, compromised mobile data are the risks. An example mobile ransomware attack is an Android ransomware app locking screens and demanding payment in crypto currency. Simplocker was one of the first known mobile ransomware strains that encrypted files on Android devices and demanded a ransom.

Which Type of Ransomware Is the Most Dangerous?

The most dangerous type of ransomware is the one that causes the biggest data loss, system downtime, and financial damage. This includes the difficulty in recovery, risk of data exposure, and the scale of attacks. The term "dangerous" is measured with the potential of the damage. There is irreversible data loss, critical systems are locked or down for an unacceptable amount of time. The ransom payments can be only a part of the financial damage if we consider loss of high-value data or market value of the company etc… Payments for recovery efforts and the cost of being down and not running, is another whole level. In imaginary worst case scenarios, a ransomware attack could have the potential to wreck an autonomous car, lock people out of houses with smart locks, and temper with HVAC systems. Health monitoring, implants, and cardiac devices connected to networks may also be the target of ransomware. Internet-connected automobiles and smart home appliances are enticing new targets. While the Internet of Things (IoT) presents many opportunities, it lacks security standards.

The difficulty of recovery is a key factor and the risk of sensitive data being leaked adds to the damage. In case the backups are insufficient or compromised, the level of danger goes high.

Here is few types of ransomware and most dangerous situations compared;

• Crypto Ransomware: Encrypts files on a personal or company device or network. The worst scenario is permanent loss of files or data even if you pay the ransom. If you don't have proper backup, or your backups fail. The data can be wiped or corrupted permanently. This scenario is mostly a part of warfare or a part of attacks which specifically aims to give the maximum damage, including getting high payments for ransom. Another worst case is even if your company has proper backups but this time you are threatened with your files and sensitive data to be leaked. Again, even after you pay ransom. Examples include CryptoLocker and variants like Ryuk and REvil, known for high ransom demands.

• Locker Ransomware: Locks users out of their devices or systems without encrypting files. It causes downtime but usually poses less risk of permanent data loss compared to crypto ransomware.

• Leakware (or Doxware): Threatens to publicly release stolen data if the ransom isn't paid. This adds a data exposure threat to the usual encryption or locking damage.

• Ransomware-as-a-Service (RaaS): A business model where ransomware developers lease their malware to affiliates. This boosts up the scale and frequency of attacks. Groups like LockBit and Conti operate under RaaS attacks, which are widespread and sophisticated with this method.

Criteria for danger levels are recovery difficulty, data exposure risks and the attack scale. Crypto ransomware is hardest to recover from due to encrypted files; without backups or keys, data loss is permanent. Leakware adds a public data exposure risk alongside encryption. This means double damage potential. RaaS-driven ransomware groups can target a wide range of victims globally. This fact increases the threat magnitude.

Some high-profile incidents are as follows;

• The REvil ransomware caused widespread damage with extremely high ransom demands and triple-extortion techniques involving data theft and threats.

• LockBit, a prominent RaaS group, infected major enterprises like Accenture, combining encryption with data leaks to maximize pressure.

• The Colonial Pipeline attack by DarkSide RaaS caused critical infrastructure shutdown and highlighted the massive operational impact ransomware can cause.

• Attacks like WannaCry caused global disruption by rapidly spreading and encrypting data on millions of machines.

Crypto ransomware combined with leakware features and distributed via RaaS mechanisms can be put into the most dangerous ransomware category. This type maximizes data loss risk, recovery difficulty, financial impact, and attack scale. High-profile cases like REvil, LockBit, and DarkSide illustrate the severe consequences of such threats.

What are the Most Common Ransomware Variants?

Most common ransomware variants are BlackCat (ALPHV), WannaCry, Ryuk, Maze and REvil (Sodinokibi). These variants are more common because they are technically sophisticated, profitable business models, and they hop on effective distribution tactics. They combine encryption with data theft, data leak threats and most importantly because of Ransomware-as-a-Service models. They also exploit widely used software vulnerabilities.

Ransomware variants spread more widely for a few key reasons. For instance, an exploit allowed WannaCry to act like a worm, and spread to different networks very fast and it could infect thousands of systems within minutes. This tool was developed by the NSA and was leaked to the public earlier. Being able to spread without human interaction was another special aspect of this case. This worm feature made it one of the fastest-spreading and most globally impactful ransomware attacks in history.

Unlike WannaCry's indiscriminate approach, Ryuk is known for its highly targeted "Big Game Hunting" strategy. It specifically targets large, high-value organizations like hospitals and major corporations.

Maze was one of the first ransomware types to combine file encryption with data theft. Its strength was dual threating.

REvil (Sodinokibi) is notable for its model of targeting large organizations and demanding high ransom payments. It is known for high-profile attacks like those on Kaseya and JBS.

BlackCat (ALPHV) was a ransomware as a service strain which was initially discovered in 2021. Triple-extortion techniques were employed to target companies and MSPs. The ransomware gang BlackCat triple extorts victims by threatening an addition of distributed denial-of-service (DDoS) attack if the initial demands aren't fulfilled. BlackCat (ALPHV) was easy to spread and had a big impact because it operated on a Ransomware-as-a-Service (RaaS) model. The RaaS model has dramatically lowered the technical skills required to launch a ransomware attack. It lowered the barrier to entry. With sophisticated social engineering, and exploitation of known vulnerabilities the impact is memorable.

Ransomware variant spread depends on attack vectors, automation capability, chosen target type, and extortion methods used. Crypto is the most common type of ransomware. It is double dangerous when combined with leakware as it is additional pressure on the victim.

Is Ransomware a Type of Malware or a Virus?

Ransomware is not a virus, it is a malware version. Malware is the general category of malicious software designed to harm or exploit any digital space. A virus is a special version of malware and it replicates itself with file attachment.

Ransomware is in the malware category for a reason. It does not self-replicate like a virus. It can be confusing when several cybersecurity phrases are used instead of each other. The term "virus" was frequently used to describe the initial malware attacks. The idea that viruses are the main cyberthreat was also a result of the early antivirus programs. Anything was known as a virus those days by the consumers. However, attackers' tactics have shifted and grown over the last quarter century. New malicious software kinds with distinct distribution methods, objectives, emerged and they have consequences on your systems.

• Malware is a malicious software which aims to damage or access any digital space.

• Virus is a type of malware which self-replicates by inserting its code into other software pieces, apps or files. When a virus infects a device, it installs itself and begins to function without the user's awareness. Viruses can format the hard drive, corrupt data, harm a device, and interfere with its operation. Certain viruses have the ability to multiply and spread throughout a local network. Through extensive memory usage and frequent crashes, they can slow down the device.

• Ransomware encrypts or threatens to leak data to extort money from victims. It is distinct from viruses as it does not replicate by infecting other files. If you hear a phrase like "ransomware virus" is not correct as it does not fit the categorisation. Viruses though can be used for more intricate ransomware attacks.

Many people use "virus" loosely to refer to any malicious software. At core, viruses are a subset of malware, and ransomware is another distinct subset. This misunderstanding is the reason behind being called a virus even though it is not one.

How does Ransomware-as-a-Service (RaaS) Change the Threat Landscape?

The RaaS model increases the resilience of operators and affiliates by giving opportunities to pass along the risk. The fact that an attacker no longer needs technical expertise to use these tools is one of the primary causes of the increase in ransomware attacks. The easy it is to launch such attacks, the more acceptable this becomes. Threat actors have the ability to specialize and hone their skills with RaaS. Affiliates can concentrate on creating more potent attack techniques, while developers can create malware that is more potent. "Access brokers" are a third form of cybercriminals who specialize in breaking into networks and selling attackers access points. Hackers can move more quickly and launch more attacks because of this fact.

The ransomware may be used by several hacker organizations. The inability of cybersecurity experts to conclusively link attacks to a particular group or groups may make it more difficult to identify and apprehend RaaS operators and affiliates. Affiliates may migrate to a different ransomware kit if a creator is found, and affiliates are not shut down when they are caught. To avoid detection, hackers have also been known to restructure and rename their operations.

By structuring ransomware activities like reputable franchises, RaaS grows ransomware attacks. Multi-platform ransomware builders that target Windows, Linux, virtual machines, and network storage devices come with advanced RaaS platforms. Other features include automated lateral network movement, self-deleting binaries, log wiping to avoid detection, and automated, one-click ransomware payload spreading. These make ransomware attacks faster, more widespread and devastating globally. RaaS functions economically as a revenue-sharing or subscription model in which affiliates keep the remaining funds and developers get 20–40% of ransom payments. This results in a profitable illicit enterprise with minimal initial expenditures. RaaS also has made "Big Game Hunting" attacks more common. High-value targets like hospitals, manufacturers, and government agencies are specifically targeted in this type of attack.

The competitive RaaS market incentivizes developers to constantly improve their product. This led to the rapid and sophisticated development, also evasive, and feature-rich ransomware variants. This includes the popular double extortion tactics.

What Makes Fileless Ransomware Difficult to Detect?

Malicious code that does not require the use of an executable file on the endpoint's file system is known as fileless malware. It usually runs just in RAM and is injected into an active process. The footprint is small and there is a lack of files to scan. Once the infected process is closed or the system is rebooted, the malicious code often disappears with minimal forensic evidence left behind.

Another method is when the attacker exploits a trusted Windows process by using a malicious file or link to manipulate the Windows registry. For instance, the Windows process is used to write and run fileless code into the registry after a user clicks on the link. This type of fileless malware can evade detection by modifying the registry rather than using a malicious application. This allows it to evade detection by conventional antivirus programs.

Living Off the Land (LotL) Attacks is a key tactic. Instead of introducing new, suspicious files, fileless ransomware abuses legitimate, pre-installed tools or scripting engines on the system. PowerShell, Windows Management Instrumentation (WMI) are examples for this. Also, sophisticated fileless threats can detect when they are in a simulated "sandbox" environment used for analysis. They may lie dormant or behave differently to avoid being flagged as malicious.

Signature-based antivirus software scans files on the disk for known malicious signatures. It is harder for conventional antivirus software and other endpoint security products to identify or block. In one incident, after a spam operation in the US and Europe, malicious Word documents were sent, and when opened they ran macros, and fileless malware was spread.

The rise of fileless ransomware has forced a major shift in cybersecurity from simple signature-based detection to a more sophisticated, behavior-based approach. This new focus on detection involves:

• Endpoint Detection and Response (EDR) solutions monitor and analyze the behavior of processes, system calls, and network connections in real time. They look for suspicious patterns of activity. PowerShell is a trusted tool in normal conditions. But if it executes a command to encrypt files then it is a red flag.

• Modern security tools now actively inspect memory and processes for injected or anomaly code. Monitoring how processes interact with each other gives a head start.

• Instead of looking for Indicators of Compromise (IOCs) like malicious file hashes, now the new focus is on Indicators of Attack (IOAs). They are sequences of actions that indicate a potential attack in progress. For example, a series of commands to disable security features followed by rapid file modifications would be a strong IOA for a fileless ransomware attack.

Can you Prevent Ransomware Attacks?

Yes, ransomware attacks can be prevented. The focus should be prevention strategies, not just recovery. Layered security measures should be used together with technical defenses and business practices. Technical defenses and business practices include:

• Patch and update software and operating systems.
• Employ anti-malware and new generation antivirus software.
• Firewalls and network segmentation for perimeter protection.
• Employ EDR tools, limit privileges and disable unnecessary services.
• Regular, immutable backups stored securely offline or in the cloud.
• Detailed cybersecurity training to recognize phishing and to avoid suspicious downloads and risky behaviors
• Strict password policies and multi-factor authentication.
• Restricting lateral movement and detecting anomalies early.
• Response procedures to minimize downtime in case of an attack.
• Security tools for malicious email attachment or a link to a compromised website. Scan and filter emails and web traffic to block threats before they reach an inbox.

The best strategy is a layered security approach. It is combining technical and human elements to create multiple barriers against ransomware infiltration and damage. Prevention significantly reduces the risk and impact of ransomware compared to relying solely on recovery after an attack has happened.

What are the Top Ransomware Attacks?

According to experts, ransomware is turning to an efficient way for cybercriminals to profit from unauthorized access to networks. Weekly reports of ransomware attacks surface. According to certain estimates, ransomware groups are getting better at employing artificial intelligence. This can result in launching more complex attacks at scale using agentic AI. The top ransomware attacks are defined by the scale of the attack, financial cost to the victims, and the level of affected critical operations. These attacks cause multimillion-dollar losses, widespread shutdowns, data breaches, and damage of finance and reputation. Industries most affected are those critical to infrastructure and economy. Manufacturing, transportation, healthcare, finance, and government are main examples. These "top" attacks aren't always the ones with the largest ransom payments, but rather those that caused widespread chaos, paralyzed critical services, and had a ripple effect across entire industries. In some cases data theft and extortion tactics like double or triple extortion are in place. Data is encrypted and threat of leak exists and in some cases the victim is additionally threatened by DDos attack for instance.

Some notable ransomware cases and examples are as follows.

1. Colonial Pipeline (2021): This attack was a defining moment as it directly targeted critical U.S. infrastructure. The DarkSide ransomware gang breached the pipeline's network. The company had to shut down its operations to contain the threat. This led to widespread fuel shortages and panic-buying across the East Coast of the United States. This elevated ransomware from a corporate problem to a national security issue.
2. Change Healthcare/UnitedHealth (2024): Attacked by ALPHV/BlackCat ransomware. It affected over 100 million people and cost billions.
3. Ryuk & BlackCat (RaaS): These are not single attacks but rather Ransomware-as-a-Service (RaaS) models used in highly targeted "Big Game Hunting" attacks. Ryuk, for example, is known for its customized and patient approach, where attackers spend weeks or months inside a network before deploying the ransomware. This method was used against major corporations like Universal Health Services and has resulted in ransom demands in the tens of millions of dollars. BlackCat (also known as ALPHV) is another prominent RaaS group that has targeted multiple high-profile entities, including MGM Resorts and the Change Healthcare subsidiary of UnitedHealth Group, which caused massive disruption to U.S. healthcare payment systems. The attack on Change Healthcare is considered one of the most costly and disruptive in healthcare history.
4. CDK Global (2024): BlackSuit ransomware attack disrupted auto dealerships across North America, causing over $1 billion in losses.
5. Ascension(2024): Ascension is a Catholic health organization in St. Louis. An attack was reported as Black Basta ransomware in May 2024. It prevented it from communications network access, electronic health data, and several vital patient care systems. Ascension's capacity to provide patient care was restricted, and they were forced to reroute ambulances and shut down pharmacies. In addition, the hack lost the charity an estimated $1.3 billion and exposed the personal data of almost 5 million people. Payment of a ransom is not reported.

What are the Ransomware Targets?

The sectors most targeted by ransomware attacks are listed below.

• Manufacturing with an approximation of more than half of the incidents. The reason for the heavy impact is the critical operational technology targeted.
• Transportation and logistics and disruptions in airport check-in systems.
• Industrial control systems and engineering sectors.
• Financial services, more than sixty percent affected and costs are millions per breach.
• Healthcare, government, oil, gas, electric, and communications are also significantly targeted.

Lessons learned from top ransomware cases are as follows.

• Proactive defense systems are critical especially in industrial sectors. There is a rising trend in these sectors.
• The WannaCry attack proved that exploiting known, unpatched vulnerabilities is a highly effective attack vector.
• The ones that were able to recover from these attacks did so because they had secure, tested, and offline backups.
• The ability to restore data without paying a ransom is a company's best defense
• The Kaseya and Change Healthcare attacks showed how a single breach in a third-party vendor's software can spread ransomware to thousands of their clients.
• Double extortion tactics are getting more common.
• Recovery costs often exceed much more than the ransom paid.
• Downtime costs and brand reputation damage can be devastating
• Ransomware groups evolve quickly especially with the use of RaaS. The rise of RaaS models like Ryuk and BlackCat indicates that modern ransomware is an organized, for-profit enterprise. They are patient, strategic, and conduct reconnaissance to maximize their impact and profit.

What is an Example of a Crypto Ransomware Attack?

Your important data, including papers, images, and videos, is encrypted by crypto ransomware, which does not affect your computer's most fundamental operations. There is a time limit in most cases. All of your files are erased if you don't make the payment before the due date. Because they have no other option for recovering their files, many users paid the ransom because they failed to see the significance of backing up their data externally.

One of the most notable crypto ransomware attacks is the WannaCry incident that happened in May 2017. It affected hundreds of thousands of computers in over 150 countries.

WannaCry spread by a vulnerability in the Server Message Block (SMB) protocol of unpatched versions of old Windows operating systems. The malware leveraged an exploit known as EternalBlue. It was developed by the U.S. National Security Agency and later leaked by a hacking group. WannaCry acted like a worm after getting in a device. It scanned for other weak devices in the network and spread itself without any user interaction. Hospitals, universities, government agencies, and corporations, were affected and critical services were affected.

The impact was far-reaching and corruptive. It even made an appearance on Russian and UK government networks. The UK's National Health Service (NHS) was severely affected. Appointments in hospitals were stopped, and systems were shut down. Nissan's UK plant and FedEx also reported significant damage. The attack caused billions of dollars globally. Some reports said that even after paying the ransom, some users still did not recover their data.

WannaCry was a ransomware that utilised worm features. It turned into a fast-spreading autonomous threat. Ransomware normally depends on a user to click a link or open an attachment. It demonstrated how a single vulnerability could be exploited to cause a global crisis.

One of the most destructive ransomware attacks was the NotPetya outbreak in Russia in 2017. Over 2,000 firms globally were impacted by NotPetya, including several major players in the industry. NotPetya was a ransomware wiper created more for chaos and devastation than for profit. allegedly with the intention of attacking the Ukrainian government. The US EternalBlue penetration tool, likewise utilized in the WannaCry attack, was exploited by the ransomware. NotPetya might quickly propagate over networks by posing as a standard update for accounting software.

Is Ransomware a Trojan?

No, ransomware is not a Trojan, but they are closely related. The main relation is that ransomware is often delivered by Trojans.

Ransomware is a type of malware, while a Trojan is a specific delivery method for it. A Trojan is the disguise, and ransomware is the malicious payload.

A Trojan is a kind of malware that is distinguished by its primary feature, which is a deceitful method of delivery. Its main way to get in is to pose as trustworthy software or app, or at least a harmless one. A Trojan cannot replicate or propagate on its own like a virus or worm. It depends on social engineering to enter a system, like phishing emails or an infected app download. A specific and intentional user activity, like clicking on a phony advertisement, opening a malicious email attachment, or launching a corrupted program, is their method to be activated. Its function in the attack chain is defined by its fundamental reliance on human behavior.

A Trojan's payload can carry out a variety of harmful tasks when it has successfully compromised a machine. The way a trojan employs to obtain access to a network defines its purpose, not what it does once inside. For example, a Trojan may establish a permanent remote access backdoor that would allow an attacker to take over the compromised device and install other software. Or a trojan hidden in an email attachment can come with ransomware that then encrypts files and demands ransom. While Downloader Trojans focus on retrieving and installing other malicious applications from a remote server, other types, like Banker Trojans, are made to steal banking credentials. Because of its adaptability, the Trojan is a very powerful and fundamental tool for a broad range of cyberattacks.

The primary goal of ransomware, on the other hand, is financial extortion. Denying a user or a business access to their files, systems, or network and then requesting a ransom to restore them is its primary operational role. Complex encryption algorithms turn data unreadable. Unless paid for the decryption key. In order to hide and not to be caught, the ransom asking method from the victim usually includes detailed payment instructions. One way is hard-to-track cryptocurrencies like Bitcoin. The relation with trojans is, it is frequently spread by a Trojan that first infiltrates the victim's computer pretending to be a trustworthy application or attachment.

Feature	Trojan Horse	Ransomware	Relationship
Primary Purpose	Deception for Initial Access	Financial Extortion	Not the same
Method of Impact	Creates backdoors, steals data, or downloads other malware	Encrypts files, locks systems, threatens to leak data	A Trojan is the initial entry point; ransomware is the final action
Replication/Propagation	Requires user action as an infected attachment	Can be self-propagating as worm or requires a delivery vector	A Trojan is a delivery vehicle, but not the only one
Classification	A broad category of malware	A specialized category of malware	Both are subsets of malware, but with distinct functions

Table 1: Differences and the relationship between trojan and ransomware