What is a Keylogger | Threat Strategies, Common Harms, and Measures

A Keylogger is a generic term for a program that tracks keyboard inputs to the computer. Because of the repeatedly occurring Keylogger incidents that caused information exploits, the term is considered negatively associated with malicious activities.

Although the security impact caused by Keylogger can be quite harmful, there are many research and studies conducted to reduce the infection.

In this article, we will learn the definition of Keylogger, the different types, and proper measures to prevent from being attacked.

Keylogger Definition

Keylogger is, as the name implies, a hacking tool to record or track keyboard operations.

A Keylogger has quite a long history and been used since the invention of computers. The tool was originally used to verify and debug programming development and monitor network communication.

Due to the powerful feature, the misusage of Keylogger leads to inventing many new hacking techniques to steal confidential information and became a critical problem throughout the world.

The term Keylogger was originally used harmlessly. However, because of the recent criminal incidents that involve Keylogger usage, now it has become considered as a negative term related to threat activities.

Over time Keylogger was less used for the original usage and more often for illegal purposes. The most common way of using Keylogger for criminal activity is to steal user credentials such as username, password, and financial accounts through tracking inputs sent from the hiddenly installed Keylogger.

What Harm Can Keylogger Cause?

The main reason to maliciously use a Keylogger is to steal confidential information. There are a variety of criminal activities that benefit from collecting sensitive data from a person or organization.

Unauthorized Account Access

Computer login usernames and passwords are often extracted by Keylogger to access the computer directly or remotely. Although most Keylogger applications start after the login, rootkit based Keylogger and hardware types can start storing keystrokes before the login.

Access information to online services brings tremendous value to hackers as it can be sold on dark web communities or use the account for criminal activities.

Confidential Information Leakage

Email address and content details exposure may lead to revealing confidential decisions related to business and institution.

Also in case a financial information fraud, critical harms can be caused to credit scores or money get stolen by unauthorized transactions.

There are several incidents that pre-announced organizational news got exposed or company finance got impacted through attack driven by hardware Keylogger.

Advanced Exploit

A Spyware designed to install a package of spy applications can collect a variety of user operations through multiple inputs. For example, a hacker can record user keystrokes while capturing a screenshot and track mouse movements.

By combining Keylogger with other spy tools, it can become a powerful strategy to perform advanced exploit attacks.

In summary, the following are the common information that gets targeted by Keylogger activities.

  • Online banking username, password, and personal secrets.
  • Credit card number, expiration date, and payment transaction.
  • Email addresses and contents.
  • Login credentials for SNS and other online services.

Common Types of Keylogger

A Keylogger can be categorized into two types, software type, and hardware type.

Keylogger Software

Software Keylogger is installed on a device to track any user inputs.

Usually, the software is sent and installed through email attachment similar to any malware infection method. There are also incidents that a disguised Keylogger application was hosted as free software on a website or forum to attract more users' downloads.

Keylogger Hardware

Hardware Keylogger is setup by physically attaching to the computer through a USB port. Typically the hardware type is attached between the computer and the keyboard as a small extension.

While the hardware will seamlessly stream the key inputs to the computer, all input logs are constantly getting stored so that hackers can later analyze.

A hardware type of Keylogger is difficult to be detected by security software as it is outside of the discovery domain. The visual look of the Keylogger seems like a typical hardware gadget which makes it hard for the user to give concern.

Recently the hardware Keylogger evolved to use a Wi-Fi access point to transmit key input information over the network.

Keylogger Threats for Smartphone

A Keylogger threat does not only occur against computers but also for smartphones.

Security specialists discovered that a rootkit called Carrier IQ was capable of recording every virtual keyboard inputs on both Android and iOS smartphone devices.

Because most smartphone operating systems apply an extra layer between the application and itself, any application that gets installed to the device will not be able to analyze the keystrokes.

However, under some specific circumstances such as Jailbreak or Rooted smartphones, a custom application becomes capable to access the keystroke stream. Downloading a custom application from an unauthorized website is the most common reason that smartphone gets infected by Keystroke software.

Ways to Find If Keylogger is Used

Software Type

Software Keylogger is most likely impossible to be discovered by the user because it is designed to be invisible by nature. Unlike other malware, Keylogger does not require much resource consumption and will not cause performance slowdown in any way.

To discover software Keylogger, the best approach is to use antimalware software dedicated to scan Keylogger activities.

Hardware Type

On the other hand, hardware type Keylogger cannot be discovered by antimalware software as logging activities are performed outside of the computer.

To detect if hardware Keylogger is used or not, check for any unfamiliar or suspicious device attached to the computer. There is a high chance that Keylogger is applied to the cable between the keyboard and the computer.

How to Prevent Yourself from Keylogger Threats

Keylogger threats can be prevented by paying extra care to not be infected in the first place.

Similar to viruses and malware infection, Keylogger threats can be avoided through the following.

  • Install an appropriate security application or antimalware software.
  • Avoid installing suspicious applications or software, especially from unofficial websites and P2P communities.
  • Do not open malicious emails and attachment files.
  • Check around the computer and look for unfamiliar device attachment.

Understanding threat characteristics and security practices is the solution to protect ourselves from infections.