Clone phishing is a sophisticated and insidious type of phishing attack that capitalizes on the trust and familiarity of legitimate email communications. Unlike traditional phishing, which often involves sending fake emails from seemingly random or suspicious sources, clone phishing requires a subtler approach. Attackers first obtain a legitimate email that the prospective has previously received. This can be done through various means, such as for instance hacking into the e-mail accounts of trusted contacts or intercepting emails via compromised networks. Once the attacker has got the legitimate email, they create a defined replica or "clone," but with malicious links or attachments substituted for the original ones. The cloned email is then delivered to the original recipients, making it appear as if it's an extension or follow-up of a prior legitimate conversation.

The potency of clone phishing lies in its ability to exploit the trust that recipients have in known senders and familiar email formats. When recipients see a contact that appears to come from a trusted clone phishing and references a previous interaction, they are more prone to click on links or open attachments without suspicion. This is particularly dangerous in a business context, where employees frequently receive and respond to emails from colleagues, clients, and partners. The cloned email can contain malicious software, such as for example ransomware or spyware, or lead the recipient to a fake website built to steal login credentials and other sensitive information.

One of the main challenges in defending against clone phishing is the difficulty in distinguishing cloned emails from legitimate ones. Attackers head to great lengths to produce their cloned emails appear authentic, replicating not merely the content but also the sender's email and even the email signature. Advanced cloning techniques can also involve mimicking the writing style and tone of the initial sender, which makes it even harder for recipients to detect the fraud. Traditional email security measures, such as for instance spam filters and antivirus programs, may not be sufficient to catch these sophisticated attacks, especially if the cloned email originates from a compromised account within the same organization.

To combat clone phishing, organizations must adopt a multi-layered way of email security. This includes using advanced email filtering solutions that may detect anomalies in email metadata and content, implementing strong authentication mechanisms like multi-factor authentication (MFA), and regularly updating security software to protect against the latest threats. Employee training and awareness programs are also crucial, as human vigilance is usually the last type of defense against phishing attacks. Employees ought to be trained to acknowledge the signs of phishing, such as unexpected requests for sensitive information, unusual links or attachments, and discrepancies in email content or formatting.