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Keylogger
Definition
A keylogger is software or hardware that records all keystrokes made by a user. Attackers use keyloggers to steal passwords, credit card numbers, and other sensitive information.
A keylogger is software or hardware that records all keystrokes to steal sensitive information including passwords, credit card numbers, messages and other confidential data. Keyloggers are one of the oldest and most effective credential theft methods, used by both cybercriminals and advanced threat actors.
How does a keylogger work?
Software keyloggers install as malware and intercept keystrokes at kernel level or via API hooks. Every keystroke is logged and periodically sent to the attacker via an encrypted C2 connection. Advanced keyloggers also capture screenshots, clipboard content and browser form data. Hardware keyloggers are physical devices placed between keyboard and USB port, storing all keystrokes in internal memory.
Types of keyloggers
Kernel-level keyloggers operate at the deepest system level and are hardest to detect. API-level keyloggers intercept keyboard API calls. Form grabbers specifically capture browser form data. Memory-injection keyloggers inject code into running processes. Acoustic keyloggers analyse keystroke sounds. Hardware keyloggers require physical access but are invisible to software detection.
Impact on organisations
Keyloggers are deployed in targeted attacks to harvest credentials for lateral movement and privilege escalation. Banking Trojans use keyloggers for financial credential theft. APT groups deploy keyloggers for long-term espionage. Stolen credentials can lead to data breaches, financial fraud and full system compromise.
Protection
EDR solutions detect keylogger behaviour via behavioural analysis. MFA reduces risk since stolen passwords alone are insufficient. Password managers with auto-fill bypass keyboard input. Physical inspections detect hardware keyloggers. Monitor for unusual outbound data flows.
How DEFION helps
DEFION detects keyloggers through Managed Threat Detection. Pentests test whether keylogger malware can bypass endpoint security measures.