Clone phishing is a sophisticated and insidious form 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 takes a subtler approach. Attackers first obtain a legitimate email that the prospective has previously received. This can be achieved through various means, such as for example 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 an exact replica or "clone," but with malicious links or attachments substituted for the initial ones. The cloned email is then delivered to the original recipients, making it appear as if it's a continuation or follow-up of a prior legitimate conversation.

The effectiveness of clone phishing is based on its power to exploit the trust that recipients have in known senders and familiar email formats. When recipients see a message that appears in the future from a trusted source and references a prior interaction, they are more likely to select links or open attachments clone phishing suspicion. This is specially dangerous in a business context, where employees frequently receive and answer 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 phony website made to steal login credentials or other sensitive information.

Among the main challenges in defending against clone phishing is the problem in distinguishing cloned emails from legitimate ones. Attackers visit great lengths to make their cloned emails appear authentic, replicating not just the content but also the sender's email address and even the email signature. Advanced cloning techniques may 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, might not be sufficient to catch these sophisticated attacks, especially when the cloned email comes from a compromised account within exactly the same organization.

To combat clone phishing, organizations must adopt a multi-layered way of email security. Including using advanced email filtering solutions that will 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 may also be crucial, as human vigilance is often the last distinct 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.