What is a Trojan horse? Trojan Horse Viruses and Malware Explained | fortinet (2023)

Download the ebook - Use AI to Detect Malware

What is a Trojan horse virus?

A trojan horse virusis a type of malware that is downloaded onto a computer disguised as a legitimate program. Delivery method is typically used by an attackerSocial developmentHiding malicious code in legitimate software to try to trick users into the system with their software.

A simple way to answer the question "what is trojan" is a type of malware that is usually hidden as an email attachment or a free downloadable file and then delivered to the user's device. Once downloaded, the malicious code performs the task for which the attacker developed, for example, gaining access to company systems through backdoors, spying on users' online activities or stealing confidential data.

Signs that a Trojan is active on a device include unusual activity, such as unexpected changes to computer settings.

(Video) What is a Trojan Horse and How Does It Work?

Trojan horse history

The original story of the Trojan Horse is found in Virgil's Aeneid and Homer's Odyssey. In the story, the enemies of the city of Troy managed to enter through the city gates with a horse, which they pretended to be a gift. The soldiers hid in the huge wooden horse, and once inside, they got out and let the other soldiers in.

There are some elements of the story that make the term "Trojan horse" an appropriate name for them.Types of cyber attacks:

  • The Trojan horse was a unique solution to target defense. In the original story, attackers besieged the city for 10 years and failed to defeat it. The Trojan Horse gave them the access they wanted a decade ago. A Trojan horse virus can also be a good way to protect yourself from a tight defense.
  • The Trojan horse appeared to be a legitimate gift. Likewise, a Trojan horse looks like legitimate software.
  • Trojan Horse soldiers controlled the city's defense system. With a Trojan horse virus, malware takes control of your computer, leaving you potentially vulnerable to other "intruders".

What is a Trojan horse? Trojan Horse Viruses and Malware Explained | fortinet (1)

How do Trojan horses work?

not howcomputer virus, ATrojan Horseit cannot manifest itself, so the user must download the server side of the app for it to work. This means that the executable (.exe) file must be deployed and the program must be installed for the Trojan to attack a device's system.

A Trojan horse spreads via seemingly legitimate emails and email attachments, which end up as spam in the inboxes of as many people as possible. When the email is opened and the malicious attachment is downloaded, the Trojan server is automatically installed and launched every time the infected device is turned on.

Devices can also be infected with a Trojan horse through social engineering tactics, which cybercriminals use to coerce users into downloading a malicious application. The malicious file can be hidden in banners, pop-up ads or links on websites.

A computer infected with Trojan horse malware can also spread it to other computers. A cybercriminal turns the device into a zombie computer, which means they can remotely control it without the user's knowledge. Hackers can use the zombie computer to continue sharing malware through a network of devices called a botnet.

For example, a user might receive an email from someone they know that contains an attachment that also looks legitimate. However, the attached file contains malicious code that executes and installs the Trojan on your device. Often, the user is unaware that something unusual has happened, as their computer can continue to function normally without any signs of infection.

(Video) What is a Trojan Horse Virus?

The malware remains undetected until the user performs a specific action, for example B. visiting a specific website or banking application. This activates the malicious code and the Trojan performs the action desired by the hacker. Depending on the type of Trojan and how it was created, the malware may be removed, inactive or remain active on the device.

Trojans can also attack and infect smartphones and tablets with a variety of mobile malware. This can be done by the attacker by redirecting traffic to a device connected to a Wi-Fi network and then using that to launch cyber attacks.

The most common types of Trojan horse malware

There are many types oftrojan virusthat cybercriminals use to carry out different actions and different attack methods. The most common types of Trojans include:

  1. Trojans the backdoor:A backdoor Trojan horse allows an attacker to remotely access and control a computer through a backdoor. This allows the bad actor to do whatever he wants to the device, for example B. Delete files, restart the computer, steal data or upload malware. A backdoor Trojan is commonly used to create a botnet on a network of zombie computers.
  2. banking trojan:A banking Trojan aims to attack users' bank accounts and financial information. It tries to steal account details of credit and debit cards, electronic payment systems and online banking systems.
  3. Distributed Denial of Service (DDoS) Trojan:These Trojan programs carry out attacks that flood the network with traffic. Sends multiple requests from a computer or group of computers to overload the target web address and cause a denial of service.
  4. Trojans de download:A Trojan downloader targets a computer that is already infected with malware and then downloads and installs additional malware onto it. These can be additional trojans or othertypes of malwareas adware.
  5. Exploitation Trojans:An exploitative malware program contains code or data that exploits specific vulnerabilities in an application or computer system. The cyber-criminal will attack users using a method such as a phishing attack and then use program code to exploit a known vulnerability.
  6. fake antivirus trojan:A rogue antivirus Trojan mimics the actions of legitimate antivirus software. The Trojan is designed to detect and remove threats like regular antivirus software and extort users to remove threats that may not exist.
  7. game stealer trojan:A game-stealing Trojan is specifically designed to steal account information from users who play online games.
  8. Instant Messaging (IM) Trojans.:This type of Trojan horse targets instant messaging services to steal user usernames and passwords. It targets popular messaging platforms like AOL Instant Messenger, ICQ, MSN Messenger, Skype and Yahoo Pager.
  9. Information Stealing Trojan: This malware can be used to install Trojan horses or prevent the user from detecting the existence of a malicious program. Trojan Infostealer components can make it difficult for antivirus systems to detect them during scans.
  10. Trojan horse email finder:A Mailfinder Trojan aims to collect and steal email addresses that have been stored on a computer.
  11. ransom trojans:Ransomware Trojans attempt to slow down a computer's performance or lock data on the device so that the user can no longer access or use it. The attacker will withhold the ransom from the user or organization until they pay a ransom fee to reverse the device damage or unlock the affected data.
  12. Remote Access Trojan: Similar to a backdoor Trojan horse, this type of malware gives the attacker complete control over the user's computer. The cybercriminal maintains access to the device through a remote network connection, which he uses to steal information or spy on a user.
  13. Rootkit-Trojaner:Arootkitis a type of malware that hides on the user's computer. Its purpose is to evade malware detection, allowing malware to remain active longer on an infected computer.
  14. Short Message Service (SMS)-Trojaner:An SMS Trojan infects mobile devices and can send and intercept text messages. This includes sending messages to premium phone numbers, increasing the cost of the user's phone bill.
  15. spy trojans:Spy Trojans are designed to reside on a user's computer and spy on their activities. This includes logging keystrokes, taking screenshots, accessing the apps they use, and tracking login credentials.
  16. PUZZLE: The SUNBURST Trojan virus has been released on multiple SolarWinds Orion platforms. Victims were compromised with Trojanized versions of a legitimate, digitally signed SolarWinds file called SolarWinds.Orion.Core.BusinessLayer.dll. The Trojanized file is a backdoor. Once on the target computer, it sits idle for a period of two weeks and then retrieves the commands that allow it to transfer, run, explore, restart and stop system services. Communication takes place via http to specified URIs.

How to recognize a trojan horse virus

A Trojan horse virus can often remain on a device for months without the user even knowing that their computer has been infected. However, telltale signs of a Trojan horse include sudden changes to your computer's settings, loss of computer performance, or unusual activity. The best way to detect a Trojan horse is to scan a device with a Trojan horse scanner or malware removal software.

How to protect yourself from trojan viruses

A Trojan horse virus can often remain on a device for months without the user even knowing that their computer has been infected. However, telltale signs of a Trojan horse include sudden changes to your computer's settings, loss of computer performance, or unusual activity. The best way to detect a Trojan horse is to scan a device with a Trojan horse scanner or malware removal software.

(Video) Trojan Malware Explained

Examples of Trojan virus attacks

Trojan horse attacks are responsible for great damage, infecting computers and stealing user data. Known examples of Trojans are:

  1. Rakhni-Trojaner:The Rakhni Trojan delivers ransomware, or a cryptojacking tool, that allows an attacker to use a cryptocurrency mining device to infect devices.
  2. Little banker:Tiny Banker allows hackers to steal users' financial data. It was discovered to infect at least 20 US banks.
  3. Zeus or Zbot:Zeus is a financial services-oriented toolkit that allows hackers to create their own Trojan malware. The source code uses techniques such as form capture and keystroke logging to steal user credentials and financial data.

How Fortinet can help

HeFortinet Antivirus Services.Harness the power of FortiGuard Labs' Global Threat Intelligence system. In one minute, FortiGuard eliminates an average of 95,000MalwareFortiGuard programs do this by incorporating their knowledge of different types of viruses into the global threat landscape. Countermeasures are designed to neutralize each type of threat and are automatically deployed by FortiGuard, protecting networks under the FortiGuard umbrella.

The FortiGuard antivirus system comes with FortiGate, FortiSandbox, FortiMail, FortiWeb, FortiCache and FortiClient.

Quick Links

Free Product Demo Explore key features and functionality and experiment with user interfaces.
Resource Center Download a wide range of training materials and documents.
Free Trials Try our products and solutions.
Sales ContactDo you have any questions? We are here to help.
(Video) Trojan Virus - Why is it DANGEROUS?

FAQs

What is a Trojan horse? Trojan Horse Viruses and Malware Explained | fortinet? ›

What Is a Trojan Horse Virus? A Trojan Horse Virus is a type of malware that downloads onto a computer disguised as a legitimate program. The delivery method typically sees an attacker use social engineering to hide malicious code within legitimate software to try and gain users' system access with their software.

What is Trojan horse explanation? ›

A Trojan Horse (Trojan) is a type of malware that disguises itself as legitimate code or software. Once inside the network, attackers are able to carry out any action that a legitimate user could perform, such as exporting files, modifying data, deleting files or otherwise altering the contents of the device.

What is the difference between malware and virus and Trojan horse? ›

A Virus is a malicious executable code attached to another executable file which can be harmless or can modify or delete data. Trojan Horse is a form of malware that captures some important information about a computer system or a computer network. Antivirus softwares are used for protection against viruses.

How does a Trojan horse virus get into a computer? ›

Many users install trojans from file-sharing websites and fake email attachments. You can also get attacked from spoofed chat messages, infected websites, hacked networks and more.

What is an example of Trojan horse malware? ›

Some of the most famous discoveries include: Bitfrost, a remote access Trojan (RAT) that infected Windows clients by changing, creating and altering components. Tiny Banker, which allowed attackers to steal sensitive financial information.

What is computer malware? ›

Malware is a catch-all term for any type of malicious software designed to harm or exploit any programmable device, service or network. Cybercriminals typically use it to extract data that they can leverage over victims for financial gain.

Is Trojan horse good or bad? ›

A Trojan horse (or Trojan) is one of the most common and dangerous types of threats that can infect your computer or mobile device. Trojans are usually disguised as benign or useful software that you download from the Internet, but they actually carry malicious code designed to do harm—thus their name.

What is difference between virus and malware? ›

Malware is a catch-all term for any type of malicious software, regardless of how it works, its intent, or how it's distributed. A virus is a specific type of malware that self-replicates by inserting its code into other programs.

Is malware and Trojan the same? ›

Malware is designed to cause damage to a stand-alone computer or a networked pc. So wherever a malware term is used it means a program which is designed to damage your computer it may be a virus, worm or Trojan.

Is Trojan a virus or bug? ›

Trojans are not viruses, but they are a type of malware. People sometimes refer to “Trojan viruses” or “Trojan horse viruses,” but there's no such thing.

What happens when you get a Trojan virus? ›

A Trojan virus on a computer, or simply a Trojan, is a malicious software program or code masquerading as legitimate and harmless software. Once it infects a device, it executes its task, which may include deleting or modifying data, stealing data, installing additional malware, and disrupting system performance.

How is Trojan horse malware prevented? ›

Never download or install software from a source you don't trust completely. Never open an attachment or run a program sent to you in an email from someone you don't know. Keep all software on your computer up to date with the latest patches. Make sure a Trojan antivirus is installed and running on your computer.

Can you get a Trojan virus on your phone? ›

Trojans that run on the Android operating system are usually either specially-crafted programs that are designed to look like desirable software (e.g., games, system updates or utilities), or copies of legitimate programs that have been repackaged or trojanized to include harmful components.

What is an example of a malware? ›

Types of malware include computer viruses, worms, Trojan horses, ransomware and spyware. These malicious programs steal, encrypt and delete sensitive data; alter or hijack core computing functions and monitor end users' computer activity.

Is Trojan horse a spyware? ›

A Trojan horse program is similar to spyware except that it is packaged as another program. These programs are much like the ancient story of Troy where the Greeks presented the Trojans with a large wooden horse as a peace offering.

What are the 4 main types of malware? ›

As part of an organization's security and data protection program, it should have a plan in place that, at minimum, mitigates risk to systems and networks arising from four common types of malicious software: trojans, spyware, viruses, and ransomware.

What are 3 things malware does to a computer? ›

Malware attacks can crack weak passwords, bore deep into systems, spread through networks, and disrupt the daily operations of an organization or business. Other types of malware can lock up important files, spam you with ads, slow down your computer, or redirect you to malicious websites.

What are the 4 types of computer viruses? ›

Types of Computer Viruses
  • Boot Sector Virus. Your computer drive has a sector solely responsible for pointing to the operating system so that it can boot into the interface. ...
  • Web Scripting Virus. ...
  • Browser Hijacker. ...
  • Resident Virus.

What is the most famous Trojan horse virus? ›

ILOVEYOU (commonly referred to as the “ILOVEYOU virus”) was a trojan released in 2000, which was used in the world's most damaging cyberattack, which caused $8.7 billion in global losses.

What is the most harmful Trojan? ›

Zeus. Zeus is a Trojan horse designed to steal personal financial data such as passwords and bank details. It was first discovered in 2007 and roped infected devices into a botnet, a large network of computers controlled by hackers. Cybercriminals used the botnet to steal money from major corporations and banks.

What damage can Trojan horses do? ›

The effects of Trojans can be highly dangerous. Like viruses, they can destroy files or information on hard disks. They can also capture and resend confidential data to an external address or open communication ports, allowing an intruder to control the infected computer remotely.

What are the 3 types of viruses? ›

The Three Major Types of Computer Viruses
  • Macro viruses – These are the largest of the three virus types. ...
  • Boot record infectors – These viruses are known also as boot viruses or system viruses. ...
  • File infectors – These viruses target .

Can you tell if you have malware? ›

Scan your device for malware.

Run a malware or security Delete anything it identifies as a problem. You may have to restart your device for the changes to take effect. Run your scan again to make sure everything is clear. If the scan shows there are no more issues, you've likely removed the malware.

Is malware the same as hacked? ›

While malware is passive software usually sent out over the internet, a malicious hacker is someone that is actively working to disable security systems with the intent of either taking down a system or stealing information.

How do I know if I have a Trojan virus? ›

A common symptom of Trojan infection is the sudden appearance of apps you don't recall downloading or installing. If you notice an unfamiliar app from an unverified developer in your Windows Task Manager, there's a good chance that it is malicious software installed by a Trojan.

Are all Trojans malware? ›

A Trojan Horse Virus is a type of malware that downloads onto a computer disguised as a legitimate program. The delivery method typically sees an attacker use social engineering to hide malicious code within legitimate software to try and gain users' system access with their software.

Are Trojans a type of virus? ›

A Trojan horse, or Trojan, is a type of malicious code or software that looks legitimate but can take control of your computer. A Trojan is designed to damage, disrupt, steal, or in general inflict some other harmful action on your data or network. A Trojan acts like a bona fide application or file to trick you.

Can a Trojan virus record you? ›

Cybercriminals can use so-called Trojan horse malware. You click on an attachment or download a piece of music or video infected with malware, and hey presto! – A cybercriminal can remotely control your PC's functions – including your camera and microphone and may even be able to record images and audio remotely.

What happens if you delete a virus? ›

If you just delete the suspicious file, the malware will probably keep reinstalling itself anyway and continue causing damage to your device. This is not to say that computer viruses cannot be deleted manually—they can, but this is a very complex process that would require a lot of time and effort.

What to do after removing a Trojan virus? ›

Unfortunately your other choices are limited, but the following steps may help save your computer and your files.
  1. Call IT support. ...
  2. Disconnect your computer from the Internet. ...
  3. Back up your important files. ...
  4. Scan your machine. ...
  5. Reinstall your operating system. ...
  6. Restore your files. ...
  7. Protect your computer.

How do I know if I have a virus or malware on my phone? ›

The best way to check for malware on your phone is to use a mobile security app like free AVG Antivirus for Android. Run a scan. After installing AVG Antivirus, open the app and run an antivirus scan to find malware hidden in your device's system.

How do you tell if there is a virus on your phone? ›

If your phone does have a virus, you'll notice some changes in its behavior. A typical sign is the sudden existence of poor performance issues. Your phone might slow down when you try to open its browser or another app. Other times, you'll notice some apps behaving suspiciously.

How do you get rid of a virus fast? ›

If your PC has a virus, following these ten simple steps will help you to get rid of it:
  1. Step 1: Download and install a virus scanner. ...
  2. Step 2: Disconnect from internet. ...
  3. Step 3: Reboot your computer into safe mode. ...
  4. Step 4: Delete any temporary files. ...
  5. Step 5: Run a virus scan. ...
  6. Step 6: Delete or quarantine the virus.

What are the 3 common malware attacks? ›

Malware comes in many forms but the most common types are: Viruses. Keyloggers. Worms.

Can malware steal your password? ›

Keylogger programs enable hackers to spy on you, as the malware captures everything you type. Once inside, the malware can explore your computer and record keystrokes to steal passwords. When they get enough information, hackers can access your accounts, including your email, social media, and online banking.

How common is malware? ›

304 million reported ransomware attacks were reported globally in 2020 by experts in cybersecurity. 37,700 ransomware attacks were reported every hour of every single day in 2020. 578 ransomware attacks were reported to global authorities every single minute of every single hour of every single day of 2020.

What is an example of spyware? ›

Spyware example: Pegasus (NSO Group)

The Pegasus spyware is a well-known spyware program by the NSO Group, a technology company based in Israel. The Pegasus spyware targets mobile devices running both on the iOS and Android operating systems. It has infected devices globally since its development in 2011.

How do hackers use Trojans? ›

A hacker can use Trojans to edit and delete the files present on a victim system, or to observe the activities of the victim. Trojans can steal all your financial data like bank accounts, transaction details, PayPal related information, etc. These are called Trojan-Banker.

What antivirus can remove Trojan horse? ›

Avast's free antivirus tool for Android eliminates trojans and other malware threats while keeping your Wi-Fi connection secure.

What is the difference between spyware and malware? ›

Spyware is one type of malware that can monitor or control your computer use. It may be used to send consumers pop-up ads, redirect their computers to unwanted websites, monitor their Internet surfing, or record their keystrokes, which, in turn, could lead to identity theft.

What is the major difference between Trojans and other malware? ›

Unlike other types of malware, trojans are not self-replicating, meaning that the user has to take action and actively click on the file for the malicious software, or payload, to execute. In addition, malicious actors often use social engineering tactics to convince users to engage in risky behavior.

What is the difference between a Trojan horse and a virus quizlet? ›

A Trojan horse is software that performs unexpected or unauthorized, often malicious, actions. The main difference between a Trojan horse and a virus is that Trojan horses do not replicate. Trojan horses cause damage, unexpected system behavior, and compromise the security of systems.

Is Trojan horse not an example of malware? ›

A Trojan horse, or Trojan, is a type of malicious code or software that looks legitimate but can take control of your computer. ... A Trojan is sometimes called a Trojan virus or a Trojan horse virus, but that's a misnomer. Viruses can execute and replicate themselves.

Why is the virus called Trojan horse? ›

In computing, a Trojan horse is any malware that misleads users of its true intent by disguising itself as a standard program. The term is derived from the ancient Greek story of the deceptive Trojan Horse that led to the fall of the city of Troy.

Are all Trojans viruses? ›

However, “Trojan virus” is a misnomer, because Trojans and computer viruses are two distinct types of malware. Viruses can spread via self-replication, while Trojans do not self-replicate. Viruses often attach themselves to other software, while Trojans are software that contains malicious codes.

What are three types of malware and then explain them in more detail? ›

What are the Types of Malware?
TypeWhat It DoesReal-World Example
SpywareCollects user activity data without their knowledgeDarkHotel
AdwareServes unwanted advertisementsFireball
TrojansDisguises itself as desirable codeEmotet
WormsSpreads through a network by replicating itselfStuxnet
7 more rows

What are viruses and Trojans? ›

A virus is a program that spreads by attaching itself to other software, while a trojan spreads by pretending to be useful software or content. Many experts consider spyware programs, which track user activity and send logs or data back to the attacker, as a type of trojan.

Which is an example of malware? ›

Types of malware include computer viruses, worms, Trojan horses, ransomware and spyware.

What is the difference between viruses worms and Trojan horses and how do hackers use the to cause harm? ›

Viruses are computer programs that connect to other software or programs to harm the system, whereas worms duplicate themselves to slow down the computer system. On the other hand, rather than replicating, a Trojan horse stores critical data about a computer system or a network.

Can a Trojan virus infect a phone? ›

Trojans that run on the Android operating system are usually either specially-crafted programs that are designed to look like desirable software (e.g., games, system updates or utilities), or copies of legitimate programs that have been repackaged or trojanized to include harmful components.

Is A Trojan malware or spyware? ›

A Trojan, or Trojan horse, is a type of malware that conceals its true content to fool a user into thinking it's a harmless file. Like the wooden horse used to sack Troy, the "payload" carried by a Trojan is unknown to the user, but it can act as a delivery vehicle for a variety of threats.

What are the harmful effects of Trojan horse virus? ›

What does a Trojan do? The effects of Trojans can be highly dangerous. Like viruses, they can destroy files or information on hard disks. They can also capture and resend confidential data to an external address or open communication ports, allowing an intruder to control the infected computer remotely.

Do Trojans infect other files? ›

Unlike viruses, Trojans do not self-replicate by infecting other files or computers. Rather, a Trojan is the decoy horse, ushering in other malicious software (malware), giftwrapped to hide its nefarious intent.

Videos

1. What is a Trojan Horse?
(Tech Index)
2. How to Remove Trojan Virus from Windows?
(MalwareFox)
3. Malwares : Virus , Worm & Trojan Horse
(Student's Life)
4. What is a Trojan Horse - Trojan Horses Simply Explained in English
(Simply Explained - English)
5. Difference Between Viruses, Worms and Trojans
(thecuriousengineer)
6. What are Trojan virus?
(Shakeel Dhada)

References

Top Articles
Latest Posts
Article information

Author: Kelle Weber

Last Updated: 09/11/2023

Views: 5843

Rating: 4.2 / 5 (53 voted)

Reviews: 84% of readers found this page helpful

Author information

Name: Kelle Weber

Birthday: 2000-08-05

Address: 6796 Juan Square, Markfort, MN 58988

Phone: +8215934114615

Job: Hospitality Director

Hobby: tabletop games, Foreign language learning, Leather crafting, Horseback riding, Swimming, Knapping, Handball

Introduction: My name is Kelle Weber, I am a magnificent, enchanting, fair, joyous, light, determined, joyous person who loves writing and wants to share my knowledge and understanding with you.