Analytics Alerts

Browse the Cortex analytics alert reference.

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1 alert match the current filters. technique: T1684 ✕

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  • Suspicious DMARC result Informational Email 3 variations

    The email has a suspicious DMARC result of either fail or none, which may indicate a potential domain misconfiguration or spoofing.

    Activation:
    14 Days
    Training:
    30 Days
    Test:
    N/A (single event)
    Deduplication:
    1 Day
    ATT&CK tactics: Stealth (TA0005)
    ATT&CK techniques: Social Engineering: Impersonation (T1684.001)
    Required data: Microsoft 365 Emails
    Detector tags: Spoofing
    Attacker's goals: Impersonate internal users or familiar individuals. Trick users into clicking on malicious links or attachments.
    Investigative actions: Check the email address for any unusual spellings. Check the email address for any missing letters. Check the reason DMARC didn't pass and the action. Check if the email was delivered to the recipients based on the action taken, even though DMARC did not pass. Verify whether the sender's IP address has appeared in different log sources before and its reputation. If the message contains attachments or links, scrutinize them for any suspicious indications. Monitor further actions taken, such as file downloads or access to potentially malicious links.

    Variations

    DMARC deviation from historically compliant domain

    Informational overridden

    An email was sent from a domain that has historically passed DMARC checks but returned a suspicious DMARC result of either fail or none for the first time in the past 30 days. This deviation may indicate an attempt to spoof or impersonate a legitimate external sender. Such sudden DMARC outcome from a previously trusted external domain warrants further investigation. overridden

    DMARC failure bypassed domain policy

    Informational overridden

    An email with a DMARC result of fail was delivered to a user's Inbox, despite the sender domain having a DMARC policy of reject. This indicates the message should have been rejected according to the domain owner policy, but was instead accepted and delivered, potentially exposing the user to email spoofing or phishing. This suggests a potential policy bypass or misconfiguration in mail filtering. overridden

    DMARC failed with non-enforcing policy

    Informational overridden

    An email was received with DMARC=fail and policy=none, meaning the message failed both SPF and DKIM identifier alignment checks, but no enforcement action (quarantine or reject) was requested by the sending domain. This may indicate an overly permissive DMARC configuration on the sender side and could allow unauthenticated messages to reach users' inboxes. Such configurations are often exploited in phishing or spoofing campaigns, and should be treated with caution. overridden