Polyglot Files
In cybersecurity, a polyglot file is a single file that can be interpreted simultaneously as two or more valid file formats. It's like a chameleon, blending into different formats depending on how it's analyzed. This ability allows polyglot files to bypass traditional email protections for a few reasons potentially:
Misidentified File Type: Traditional email security often relies on file extensions (like .exe or .zip) to identify potential threats. A polyglot file might have a seemingly harmless extension (like .txt or .jpg) on the outside but contain malicious code hidden within another format on the inside. Email scanners fooled by the extension wouldn't detect the hidden threat.
Exploiting Encoding Differences: Traditional spam filters often analyze the text content of emails for suspicious keywords. Polyglot files can exploit the way text is encoded within the file. For example, a portion of the file might be encoded in a way that appears like gibberish to the filter (avoiding detection). In contrast, another part, encoded differently, holds the malicious code.
Zero-Day Advantage: Sophisticated attackers might use polyglot files to deliver new or unknown malware that hasn't been flagged by security software yet. These "zero-day" attacks exploit vulnerabilities that haven't been patched, giving the attacker a temporary edge. A polyglot file could bypass traditional filters that rely on known malware signatures.
Even though traditional email protections are constantly improving, polyglot files remain a potential threat because they offer attackers a more complex way to sneak malicious content past standard filters.
An all-in-one solution like ThreatNG, combining External Attack Surface Management (EASM), Digital Risk Protection (DRP), and Security Ratings, can offer a multi-layered defense against polyglot file threats. Here's how it would work:
EASM for Proactive Defense:
Vulnerability Hunting: EASM continuously scans the organization's external-facing assets (websites, servers, applications) for vulnerabilities. It includes identifying weaknesses in email handling systems that attackers could exploit to upload or distribute polyglot files.
Prioritization and Patching: EASM can assess the severity of vulnerabilities related to email processing. It helps prioritize patching critical vulnerabilities that could be exploited by attacks involving polyglot files.
DRP for Threat Intelligence:
Dark Web Monitoring: DRP monitors the dark web and other shady corners of the internet for mentions of the organization's data (domains, IPs, emails). It can identify instances where attackers might discuss or share polyglot files explicitly targeting the organization.
Threat Feeds and Analysis: DRP solutions aggregate intelligence feeds from various sources. It allows for identifying known malicious polyglot file campaigns or specific file signatures. With this knowledge, the organization can proactively block emails containing these threats.
Security Ratings for Vendor Assessment:
Email Security Vendor Evaluation: Security ratings can assess the effectiveness of the organization's email security vendors. It helps ensure the email filters are up-to-date and can effectively detect emerging threats like polyglot files.
Integration with Other Security Solutions:
Security Information and Event Management (SIEM): ThreatNG can integrate with a SIEM to centralize threat data from EASM, DRP, and Security Ratings. It provides a holistic view of potential polyglot attacks across different security tools, allowing faster and more informed responses.
Email Security Gateways (SEG): Insights from EASM (vulnerability assessments) and DRP (threat intelligence) can be used to configure SEG filters more effectively. It could involve blocking specific file types or extensions associated with known polyglot attacks.
Endpoint Detection and Response (EDR): EDR solutions can be used to investigate suspicious attachments or emails that bypass SEG filters. EDR can use information from EASM (vulnerability data) to prioritize investigations and identify potential footholds gained through polyglot attacks.
By combining these functionalities, ThreatNG offers a proactive approach to defending against polyglot file threats. It helps organizations:
Identify and patch vulnerabilities in email handling systems.
Gain early warning of potential attacks through dark web monitoring and threat feeds.
Ensure email security tools are configured effectively to block known threats.
Integrate threat data across different security tools for faster response.
This layered defense makes it significantly harder for attackers to exploit polyglot files and access the organization's systems.
