It is possible to spread malicious links and induce users to download malicious files by manipulating the email system and using the automatic reply function. The following is a detailed introduction: - **Principle** - **Automatic reply function exploited**: After the attacker invades the email system, he sets an abnormal automatic reply. When the user triggers the automatic reply for various reasons, he will receive an email containing a malicious link. - **Disguised to induce download**: The email content will be disguised as a normal notification, file request or attractive content to induce users to click on the link. Once clicked, the malicious file will be downloaded to the user's device, thereby stealing information or causing other damage. - **Specific means** - **Forged sender**: Display the sender of the automatic reply as a well-known organization or individual to enhance the credibility of the email. For example, disguised as a bank notification to upgrade the service to attract users to click. - **Design tempting content**: Use hot events, urgent needs, etc. to attract users' attention. For example, during the epidemic, it was disguised as a vaccination notification and contained malicious links. - **Protection measures** - **Be cautious with automatic reply emails**: Do not easily click on the links in them, especially emails from unfamiliar senders or suspicious topics. - **Verify the authenticity of the sender**: Contact relevant institutions or individuals through other reliable channels to confirm the authenticity of the email. - **Install security software**: It has the function of real-time monitoring and blocking malware to reduce the risk of being attacked.