Definition: In the context of cybersecurity and information security, a "unmasker" refers to an individual or entity that has been intentionally exposed or compromised by a malicious actor. This can be done through various means such as phishing scams, social engineering, or even data breaches. Unmaskers are often used in conjunction with other measures to prevent further exposure of sensitive information and to mitigate the impact of cyber attacks on individuals or organizations. They may also use their own knowledge or expertise to assist in identifying suspicious behavior