Email remains one of the most common vectors for cyberattacks, with malicious attachments being a preferred method for threat actors to infiltrate organizations. Despite advances in email security technologies, a staggering number of malicious attachments continue to be sent and received daily. These attachments, often disguised as legitimate files, can deliver malware, ransomware, or phishing attempts that put entire networks at risk. To combat this threat, organizations must have robust strategies in place to manage suspicious emails once they’ve been flagged by either employees or secure email gateways (SEGs).
The Scale of the Problem
The sheer volume of malicious email attachments circulating globally is alarming. Cybercriminals constantly innovate, creating new variants of malware designed to evade detection by traditional security measures. According to cybersecurity reports, millions of malicious emails are sent each day, with many successfully reaching inboxes despite existing defenses. Phishing attempts often involve attachments that seem innocuous, such as invoices, job applications, or official-looking documents, but they contain hidden threats.
Once these emails reach an employee’s inbox, they pose a significant risk. All it takes is one click on a malicious attachment to compromise an entire network. This underscores the importance of not only having technological defenses but also fostering a culture of vigilance among employees.
Flagging Suspicious Emails: The First Line of Defense
When an email is flagged as suspicious by an employee or a secure email gateway, it’s the first critical step in preventing a potential breach. Secure email gateways are designed to filter out threats before they reach the user, using techniques like spam filtering, virus scanning, and advanced threat protection. However, even the most sophisticated SEGs can’t catch everything, especially as attackers develop new methods to bypass these systems.
How to Respond to a Flagged Email
1. Automated Quarantine and Analysis: Once an email is flagged, it should be automatically quarantined to prevent any further interaction. The attachment should be sent to a sandbox environment where it can be safely analyzed. This involves observing the attachment’s behavior when executed, which helps in determining whether it is indeed malicious.
2. Threat Intelligence Integration: Organizations should integrate their email security systems with threat intelligence platforms. This allows for real-time updates on the latest threats and helps in cross-referencing flagged attachments against known malicious indicators. If the attachment matches a known threat, the system can automatically block similar emails in the future.
3. Incident Response Protocols: If an email is confirmed to be malicious, a swift incident response is necessary. This includes notifying the affected user, isolating any compromised systems, and conducting a thorough investigation to determine if the threat has spread. The organization should also review its email security policies and update them if necessary to prevent similar incidents.
4. Employee Education and Awareness: Continuous training is crucial in ensuring that employees can recognize suspicious emails. Phishing simulations and regular awareness campaigns help reinforce the importance of cautious email handling. Employees should know how to report suspicious emails and be encouraged to do so without fear of repercussions.
The CodeHunter Solution
The battle against malicious email attachments is ongoing, with cybercriminals constantly evolving their tactics. Organizations must remain vigilant and proactive in their approach to email security. CodeHunter’s patented threat hunting engine automatically scans flagged files at the binary level, providing actionable intelligence to jumpstart SOC analysts’ investigation of suspicious email files. CodeHunter is able to evaluate files in a fraction of the time it would take a human reverse malware engineer to complete the task, reducing the time files spend in quarantine and lessening the impact of malware on day-to-day business operations. By effectively managing flagged emails and investing in both technology and employee education, businesses can significantly reduce the risk of falling victim to email-borne threats. Find out how CodeHunter’s ability to detect zero-day, multi-step, and custom malware can protect your organization’s email inboxes here.
