Rule Category

FILE-OFFICE -- Snort detected traffic targeting vulnerabilities in files belonging to the Microsoft Office suite of software (Excel, PowerPoint, Word, Visio, Access, Outlook, etc.).

Alert Message

FILE-OFFICE Microsoft Office Excel protected view bypass attempt

Rule Explanation

This rule is looking for bytes within a zip file containing multiple Excel spreadsheets designed to bypass protected mode.

What To Look For

This rule will alert when malformed Excel spreadsheets designed to bypass security features are detected.

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

MITRE ATT&CK Framework

Tactic: Initial Access

Technique: Spearphishing Attachment

For reference, see the MITRE ATT&CK vulnerability types here: https://attack.mitre.org

Additional Links

Rule Vulnerability

Authentication Bypass

An Authentication Bypass occurs when there is a way to avoid providing user credentials to a system before performing restricted operations on said system.

CVE Additional Information