What Is a Keylogger Trojan?

Some viruses can monitor all of your keystrokes

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A keylogger is just as it sounds: a program that logs keystrokes. The danger of having a keylogger virus on your computer is that it can very easily keep track of every single keystroke you enter through your keyboard, and this includes every password and username.

What's more, is that a Trojan keylogger is installed along with a regular program. Trojan horse viruses are malicious programs that don't actually look dangerous. They are attached to a regular, sometimes functioning program so that it doesn't seem like anything nefarious is installed to your computer.

Trojan keyloggers are sometimes called keystroke malware, keylogger viruses, and Trojan horse keyloggers.

Some businesses use programs that log keystrokes to keep track of their employees' computer usage, as do various parental control programs that log a child's internet activity. These programs are technically considered keyloggers but not in the malicious sense.

What Does a Keylogger Trojan Do?

A keylogger monitors and logs every keystroke it can identify. Once installed, the virus either keeps track of all the keys and stores the information locally, after which the hacker needs physical access to the computer to retrieve the information, or the logs are sent over the internet back to the hacker.

A keylogger can take anything it's programmed to monitor. If you have a keylogger virus and you're using your keyboard to enter information anywhere, you can bet the virus knows about it. This is true whether it's in an offline program like Microsoft Word or an online website like your bank or social media account.

Some keystroke malware can refrain from recording the keystrokes until a certain activity is registered. For example, the program might wait until you open your web browser and access a specific bank website before it starts.

How Do Keyloggers Get on My Computer?

The easiest way for a keylogger Trojan to reach your computer is when your antivirus software is outdated or turned off (or not even installed). Virus protection tools that are not updated can not fend against new keylogger programs; they'll pass right through the AV software if it doesn't understand how to protect your computer.

Keyloggers are downloaded through an executable file of some sort, like an EXE file. That's how any program on your computer is able to launch. However, since most programs are in the EXE format, it's next to impossible to say to avoid all EXE files in an attempt to avoid keyloggers.

One thing you can watch out for, though, is where you're downloading your software. Some websites are well known for scanning all their programs before releasing them to the public, in which case you can be certain that they don't contain malware, but that isn't true for every website on the internet. Some are simply more prone to having keyloggers attached to them (such as torrents).

Check out our article How to Safely Download & Install Software for some tips on avoiding keylogger viruses.

Programs That Can Remove a Keylogger Virus

Lots of antivirus programs protect your computer against all sorts of malware, including keylogger Trojans. So long as you have an updated antivirus program running, like Avast, or AVG, you should be secure enough to thwart any keylogger attempt.

However, if you need to delete a keylogger you already have on your computer, you'll have to scan for malware manually using a program like Malwarebytes or SUPERAntiSpyware. Another option is to use a bootable antivirus program.

Some other tools don't necessarily remove keylogger viruses but instead, avoid using the keyboard so that the keylogger doesn't understand what is being typed. For example, the LastPass password manager can insert your passwords into a web form through a few mouse clicks, and a virtual keyboard lets you type using your mouse.