What is a Keylogger?
A keylogger, also known as a keystroke logger, keyboard logger, or key recorder, is malicious software that discreetly records and stores your keyboard input. It then transmits this captured information to a remote command and control (C&C) server, thereby making it accessible to hackers.
Once in possession of a victim’s keystrokes, malicious threat actors analyze the data to identify usernames and passwords, which they exploit to gain unauthorized access to secure systems.
History of Key Loggers
The history of utilizing keyloggers for surveillance can be traced back to the early computer era. Wikipedia provides a record of diverse keylogger applications in the 1970s and early 1980s, including government covert operations.
A noteworthy early incident occurred in the mid-1970s, where Soviet intelligence agents developed a remarkably ingenious hardware keylogger. These keyloggers were deployed to target IBM Selectric typewriters in the US Embassy and Consulate buildings in Moscow and St. Petersburg. Once installed, these devices measured subtle changes in the regional magnetic fields of the typewriters as the print head rotated and typed each letter. It’s noteworthy that Soviet embassies preferred manual typewriters for classified information to avoid electric ones.
While various forms of keylogging have a long history, the proliferation of commercial keyloggers gained momentum in the mid to late 1990s, with many products entering the market during that period. Since then, the market for commercial keyloggers has expanded significantly, offering thousands of products designed for various purposes and audiences, available in multiple languages.
Historically, keyloggers primarily targeted home users for fraudulent activities. However, in recent times, industry and state-sponsored keylogging have become a serious concern. These incidents often involve phishing campaigns that compromise low-level employees or officials and work their way up the organizational hierarchy.
Types of Keyloggers
Some keyloggers exist as hardware devices that are integrated into your computer’s internal hardware. Alternatively, there can be a discreet plug inserted between the CPU unit and the keyboard cable. In either scenario, a person must physically insert this hardware into your PC or its associated peripherals. Achieving this covertly would necessitate a degree of secrecy.
The second category of keyloggers comprises software that can be easily installed on a victim’s devices. While this software is a form of malware, it falls into the category of “benign” malware, meaning it doesn’t harm the host system. Its primary function is secretly recording keystrokes without affecting the computer’s regular operation. So, while you continue your activities, these hidden keyloggers quietly steal personal or sensitive data without your knowledge.
How do Keyloggers work?
The functioning of a keylogger depends on its type. Hardware and software keyloggers operate differently due to their specific characteristics.
Most computer keyboards are connected to the back of the computer, typically hidden from the user’s view. A hardware keylogger can take the form of a module that is inserted inside the keyboard itself. As the user types on the keyboard, the hardware keylogger records each keystroke and stores it as text on its own hard drive, which can have a memory capacity of several gigabytes.
To retrieve the accumulated data, the person responsible for installing the keylogger must return and physically uninstall the device. Additionally, there are wireless keylogger sniffers that can intercept and decode data packets exchanged between a wireless keyboard and its receiver.
A typical software keylogger usually comprises two files placed in the exact location: a dynamic link library (DLL) file responsible for recording and an executable file that installs the DLL and activates it. This keylogger software captures every keystroke the user enters and regularly transmits this data over the internet to the individual who installed the program.
Hackers can develop keylogging software that utilizes various methods, such as keyboard application program interfaces (APIs), to interact with other applications, malicious script injections, or memory injections.
Detection & Removal of Keyloggers
As keyloggers employ various techniques, there needs to be a singularly effective method for detection or removal. More than simply examining a computer’s Task Manager may be required, as keyloggers can manipulate an operating system’s kernel.
Security software, including anti-keylogger programs, is specifically designed to identify software-based keyloggers by comparing computer files with a database of keylogger signatures or a checklist of common keylogger characteristics.
Using anti-keylogger software can often be more successful than relying on antivirus or antispyware programs, as the latter might mistakenly classify a keylogger as a legitimate program rather than spyware.
Depending on the methods employed by an antispyware application, it may be capable of identifying and deactivating keylogger software with lower privileges than it possesses. Employing a network monitor can provide users with alerts whenever an application attempts to establish a network connection, enabling a security team to intercept potential keylogger activity.
How to Protect Yourself from Keyloggers
To enhance the security of your devices against keyloggers, it is crucial to utilize high-quality antivirus or firewall protection. Additionally, there are several proactive measures you can take to reduce the risk of infection.
One effective strategy is to employ a password manager, which can generate highly intricate passwords and offer a convenient overview of your login credentials. A significant number of these applications include an auto-fill function, reducing the necessity for manual keystrokes.
Keep in mind that a keylogger is only effective when you are actively typing. By using a password manager with auto-fill, even video surveillance is unable to discern the characters being entered, as they are typically replaced by asterisks.
Furthermore, whenever possible, opt for multi-factor authentication (MFA) to add an extra layer of security. While a keylogger may capture your password, the second phase of the authentication process can act as a deterrent.
Another useful approach is to employ a virtual keyboard, which can effectively thwart keyloggers. Even hypervisor-based keyloggers, operating beneath your primary system, are unable to capture keystrokes made on a virtual keyboard.
Lastly, it is advisable to regularly inspect the hardware connections on your computer. While hardware keyloggers are less prevalent, the back of a PC’s tower can be an attractive target for potential keylogging attackers. This is particularly relevant when using public computers, where an attacker may have clandestinely installed a hardware keylogger days or weeks prior to your use, potentially compromising sensitive accounts like your bank, brokerage, or email.
What is a keylogger used for?
A keylogger, whether malicious software or hardware, captures and logs the keystrokes entered while you type, then transmits this data to a hacker through a command-and-control (C&C) server.
Who uses a keylogger?
Keyloggers can find applications in various scenarios. Employers may utilize them to monitor the computer activities of their employees, ensuring compliance with company policies. Parents employ keyloggers to supervise and safeguard their children’s online behavior, promoting a secure digital environment. Additionally, individuals may use keyloggers to track and identify unauthorized or suspicious activities on their devices, enhancing personal security. Furthermore, law enforcement agencies may deploy keyloggers to investigate and analyze incidents related to computer use, aiding in digital forensics and cybercrime detection.
Is it illegal to have a keylogger?
Yes, keylogger usage is legal if it is not employed for malicious purposes. Employers commonly use keyloggers to monitor and oversee their employees’ computer activities. Similarly, parents may use keyloggers to establish parental control and ensure a secure online environment for their children.
How do mobile devices get keyloggers?
Keyloggers on Android devices are frequently installed through text messages. If you receive an unexpected or suspicious text, refrain from clicking on any embedded links. Watch for unusual behavior on your phone, such as unexpected power cycling, as keyloggers can disrupt your operating system, leading to malfunctioning.
How can I tell if I have a keylogger infection?
Detecting a possible keylogger infection involves monitoring your computer for unusual behavior, frequent crashes, slow performance, and unexpected pop-ups. Use trusted anti-malware tools for regular scans and stay vigilant about unfamiliar software or network activity. If suspicion arises, change your passwords and consider professional help to secure your device.