Definition of trojan viruses

Game-thief Trojan : A game-thief Trojan is specifically designed to steal user account information from people playing online games. Infostealer Trojan : This malware can either be used to install Trojans or prevent the user from detecting the existence of a malicious program.

The components of infostealer Trojans can make it difficult for antivirus systems to discover them in scans. Mailfinder Trojan : A mailfinder Trojan aims to harvest and steal email addresses that have been stored on a computer. The attacker will then hold the user or organization ransom until they pay a ransom fee to undo the device damage or unlock the affected data.

The cyber criminal maintains access to the device through a remote network connection, which they use to steal information or spy on a user. Its purpose is to stop malicious programs from being detected, which enables malware to remain active on an infected computer for a longer period. This includes logging their keyboard actions, taking screenshots, accessing the applications they use, and tracking login data.

Victims were compromised by trojanized versions of a legitimate SolarWinds digitally signed file named: SolarWinds. The trojanized file is a backdoor. Once on a target machine, it remains dormant for a two-week period and will then retrieve commands that allow it to transfer, execute, perform reconnaissance, reboot and halt system services.

Communication occurs over http to predetermined URI's. How To Recognize a Trojan Virus. Examples of Trojan Horse Virus Attacks.

Well-known examples of Trojans include: Rakhni Trojan: The Rakhni Trojan delivers ransomware or a cryptojacker tool—which enables an attacker to use a device to mine cryptocurrency—to infect devices. It was discovered when it infected at least 20 U.

Zeus or Zbot: Zeus is a toolkit that targets financial services and enables hackers to build their own Trojan malware. The source code uses techniques like form grabbing and keystroke logging to steal user credentials and financial details. How Fortinet Can Help.

Quick Links. A daily challenge for crossword fanatics. Love words? Need even more definitions? Ask the Editors 'Everyday' vs. What Is 'Semantic Bleaching'? How 'literally' can mean "figuratively". Literally How to use a word that literally drives some pe Is Singular 'They' a Better Choice? This means they either have to be downloaded manually or another malware needs to download and install them. Trojans often use the same file names as real and legitimate apps. It is easy to accidentally download a trojan thinking that it is a legitimate app.

Download and install other malware, such as viruses or worms. Send information about the infected device to a malicious hacker including passwords, login details for websites, and browsing history.

The Pegasus software from the Israeli manufacturer NSO, for example, is distributed via the mobile phone network. Pegasus includes a powerful arsenal of interception options.

The device can be read completely, calls can be recorded, or the phone can be used as a bugging device. In Germany, too, police authorities use a state Trojan to monitor and track criminals. If surveillance software is used by the state to track and punish criminal offenses, cybercriminals have exactly the opposite in mind. In the latter case, it is all about personal enrichment at the expense of their victims. In doing so, the criminals use different programs, sometimes even entire malware chains.

How do they do it? One example may be a backdoor installed unnoticed on the computer via an infected email attachment.

This gateway ensures that further malware is loaded onto the PC secretly and silently without being noticed. Another example is a keylogger to record keystrokes such as passwords or confidential content, a banking Trojan to steal financial data, or ransomware that encrypts the entire computer and only releases the hijacked data following payment of a significant amount of bitcoin.

Notorious in this context is the malware Emotet , which periodically makes its rounds and is described as the "most destructive malware. The BSI has set up an extra page with information on Emotet. In summary:. Trojans are not only found in email attachments.

They can also "piggyback" on supposedly free programs. Once again, therefore, it is important not to use dubious sources for software downloads such as codec packs or cracked programs, even if you might save a few euros. The damage that can be caused by Trojans often exceeds the value of the software if it had been purchased through regular channels.

Incidentally, a Trojan should not be confused with a virus. Computer viruses reproduce independently, whereas a Trojan is merely a door opener — but with potentially devastating consequences. Therefore, here is a checklist on how to protect yourself and your devices from Trojans:. The Trojans mentioned here are the best-known types. What they all have in common is that they can only get onto the end device with the help of the user.

However, if you surf the web carefully, do not open email attachments without thinking, and only obtain programs from secure sources, you should be able to avoid these threats. An up-to-date operating system and an always-on virus scanner will protect you even better from Trojans. Kaspersky Internet Security. Detecting ransomware — how encryption Trojans differ.

Tips on avoiding phishing. Ransomware protection — how to keep your data safe. We use cookies to make your experience of our websites better. By using and further navigating this website you accept this. Detailed information about the use of cookies on this website is available by clicking on more information.