A rootkit is a type of malware program that enables cybercriminals to gain access to and infiltrate data from machines without being detected. It is a software program that provides privileged, root-level (i.e., administrative) access to a computer while concealing its presence. Rootkits are designed to give hackers access to and control over a target device, and they are adept at concealing their presence. Once they gain unauthorized access to computers, rootkits enable cybercriminals to steal personal data and financial information, install malware, or use computers as part of a botnet to circulate spam and participate in DDoS (distributed denial of service) attacks. Rootkits can contain multiple malicious tools, which typically include bots to launch DDoS attacks, software that can disable security software, steal banking and credit card details, and steal passwords, and keystroke loggers. Rootkits can be installed through several methods, but they typically target a vulnerability in a machine’s operating system (OS) or application on the machine. Rootkits can hide keyloggers, which capture your keystrokes without your consent, making it easy for cybercriminals to steal your personal information, such as credit card or online banking details. Rootkits can also allow hackers to use your computer to launch DDoS attacks or send out spam emails, and they can even disable endpoint antimalware and antivirus software. Rootkits are one of the most difficult malware strands to discover and remove. To safeguard your system from rootkits, you can ensure it is kept patched against known vulnerabilities, including patches of your OS, applications, and up-to-date virus definitions. You should also avoid accepting files or opening email file attachments from unknown sources and be careful when installing software and carefully read the end-user license agreements.