Like the ancient wooden horse used by the Greeks to enter Troy and destroy it, Trojan malware works stealthily and waits until an opportunity presents itself to attack your computer or mobile devices. Learn more about this dangerous type of malware and ways to safeguard both systems against attack.
Trojans often conceal themselves within legitimate-appearing files and spread across devices through social engineering techniques, infiltrating users' devices to encrypt data, launch phishing attacks or even turn their computers into part of a botnet for DDoS attacks.
What is a Trojan horse?
Computer viruses, worms and Trojan horses are all malicious programs designed to cause severe damage to a device. But they differ significantly in several key respects: Trojan horses can masquerade themselves as legitimate applications. At the same time, viruses and worms replicate by infiltrating files or systems with code from within their host operating system. Trojans do not replicate; instead, they provide backdoor access into systems for malicious actors or allow them to steal confidential data.
Like the legendary wooden horse used to enter Troy, Trojans can hide behind an innocent facade before carrying out their destructive and deceptive missions. Their effects may range from subtle changes in system behaviour to the sudden appearance of programs, files, or folders without notice from antivirus and antimalware programs - enabling Trojans to remain undetected because they resemble legitimate operating system files so closely.
Trojans, or trojan horses, steal data from devices like personal information, passwords, bank account data and financial details. Some trojans also encrypt data before demanding a ransom to unlock it; banking Trojans like Zeus and Dyre/Dyreza intercept web traffic between devices and banks and transfer login details back and forth between them.
Trojans can access webcams, take screenshots, record keystrokes, track online and off users, exploit existing vulnerabilities that remain unpatched or remedied, download other malware, open backdoors to networks and open access points for attackers. So a good security suite is key to detecting Trojans. Keep an eye out for signs like irregular system performance, sudden changes in security settings and unexpected files or programs appearing on your system, as these may indicate Trojan activity.
History of the Trojan Horse
The Trojan horse is an ancient symbol of deception and betrayal that also serves as a metaphor for anything seemingly harmless but potentially harmful. The story has been passed down for millennia and referenced throughout literature, movies, politics and even modern-day computer systems. Additionally, "Trojan horse" refers to malicious programs which appear innocent but contain malware capable of crippling systems.
The Trojan horse story from Greek mythology is one of the best-known. It tells how Achaeans won their victory against Troy and ended the ten-year siege by employing an elaborate plan involving a wooden horse: Greeks built an enormous hollow wooden horse filled with soldiers for peace gift purposes before secretly filling it at night with Greek army members, awakening its gates for their arrival and opening them themselves for battle against Troy.
According to popular belief, the Trojan horse was constructed out of wood from cornel trees considered sacred by the Trojans. Furthermore, some historians maintain that an Achaean used a Trojan horse during wartime, although this myth may often be disproved and mocked.
The Trojan horse is a timeless symbol of deception in warfare. Humans have used horses throughout history for transportation, agriculture and war - providing us with increased distance coverage while outwitting enemies more quickly than ever.
Common Types of Trojan Malware
The term Trojan horse remains relevant today when applied to anything that seems harmless at first glance but, once inside, can have devastating repercussions. This concept extends to cyber threats; hackers use Trojans as covert means of spreading their malware by infiltrating seemingly benign files that can be downloaded onto devices without being detected by security systems.
Trojans typically appear benign programs or files for download to computers and mobile devices yet contain malicious malware waiting in the background to attack or exploit systems at an appropriate moment.
Currently, the three primary Trojan malware types are backdoor Trojans - which allow remote hackers to gain entry remotely; botnet Trojans (allowing remote control of infected devices); and ransomware - which locks devices or networks and demands payment to unlock them.
Other types include banking Trojans like Zeus that allow hackers access to financial accounts; game thief Trojans which steal account information from infected gamers; SMS Trojans designed to send text messages at premium-rate numbers; and rootkit Trojans that hide or obscure other forms of malware on devices.
Unusual system behaviour, such as an abrupt decline in performance or the sudden appearance of unknown files and programs, could indicate the presence of a Trojan. It would help to remain cautious when downloading files or opening emails, as attackers may use these methods to distribute Trojans.
How Do Trojans Work?
Trojans exploit vulnerabilities in computer systems to install malware, often by masquerading as legitimate files and employing social engineering techniques to convince their victims to click, open, or download them. Once inside, Trojans can steal data, monitor activity on victims, spy on victims' activities, or cause more severe damage than previously imagined.
Some Trojans are standalone programs, while others serve as delivery vehicles for other forms of malware. Some notable Trojans were employed during massive cyberattacks like Gameover ZeuS, Emotet, and WannaCry; their success proved that criminals could profit by using Trojans to spread threats more widely.
Trojans differ from viruses in that they require user intervention to execute yet can still harm computers and mobile devices significantly. Trojans may create backdoors for unauthorized access, disable security software or alter system settings to avoid detection.
Email attachments and free software are two common routes of infection. Once clicked upon, these attachments download and execute malicious code from a Trojan. This opens a backdoor allowing cybercriminals to target the victim's device from anywhere worldwide remotely.
Infections can occur through malicious websites and apps. Trojan infections can change DNS settings, redirect browsers or change how apps appear on the screen; unfamiliar program icons appearing in either Task Manager or Desktop may indicate an infection, while sudden decreases in performance may also signal trouble.
Trojans can be identified and removed by running a full virus scan and using Microsoft Windows Disk Cleanup or Mac Disk Utility to search and delete infected files. For added peace of mind, users should restart safely before heading to the Control Panel > Add or Remove programs > Programs tab in the Control Panel to identify and uninstall Trojans from their systems.
How To Protect Yourself from Trojan Viruses?
Like the deceptively harmless wooden horses of ancient Greek myth, Trojan cyber threats appear harmless at first glance, yet once installed can do significant harm. Just as Trojan horses were used to invade Troy, cyber threats may cause data theft or join compromised device networks in an attack against further Trojan threats. Luckily there are steps users can take to defend themselves from Trojans; comprehensive cybersecurity solutions with anti-Trojan software should provide users with protection. Clario recommends purchasing premium antivirus software with this capability to combat cyber-attacks effectively.
While called Trojans, these programs don't technically fall into the category of viruses. While viruses self-replicate and spread, Trojans require user interaction to run and execute. Hiding within seemingly harmless applications, Trojans perform malicious activities, including information cancellation, censorship and replicating, and disrupting machines or networks' operations. Furthermore, specific Trojans act as backdoors by providing access without their owner's knowledge, allowing attackers to download more malware onto a device without their knowledge.
Trojan viruses can spread via several methods, including social engineering, malware advertising, and phishing emails. To stay protected against them, the best approach is never to download apps or software from unknown sources and always check the address bar of websites before entering any personal data. Doing this will allow you to identify potentially harmful files which could steal your identity, give external hackers control of your devices, or add them to a botnet. If you suspect a Trojan virus, it's wisest to contact an expert cybersecurity provider as soon as possible to remove it and ensure no further harm comes to pass.