> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/analytics-alerts/alerts-by-name/email-attachment-s-with-potentially-malicious-mime-type.md).
# Email attachment(s) with potentially malicious MIME type
### Synopsis
| Field | Value |
| -------------------- | ---------------------------------------------------------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | N/A (single event) |
| Deduplication Period | 1 Day |
| Required Data | Microsoft 365 Emails |
| Detection Modules | Email |
| ATT\&CK Tactic | Defense Evasion (TA0005), Execution (TA0002) |
| ATT\&CK Technique | Masquerading: Masquerade File Type (T1036.008), User Execution (T1204) |
| Severity | Informational |
### Description
The email message contains an attachment(s) with a potentially malicious MIME type.
### Attacker's Goals
Bypass security filters and deliver malicious content to users
* Deploy malicious attachments through emails to compromise systems, gain unauthorized access, or facilitate cyber threats.
### Investigative actions
* Carefully analyze attachments for any indications of suspicious or malicious behavior.
* Scrutinize the attachments for any suspicious indications.
* Confirm whether the attachments were successfully delivered to the recipient's mailbox.
* If the attachments were delivered successfully, verify whether the recipient downloaded them.
### Variations
Attachment(s) with potentially malicious MIME type unusual for the organization
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------------------------- |
| ATT\&CK Tactic | Defense Evasion (TA0005), Execution (TA0002) |
| ATT\&CK Technique | Masquerading: Masquerade File Type (T1036.008), User Execution (T1204) |
| Severity | Informational |
**Description**
At least one attachment with a potentially malicious file mime-type was received in an email for the first time within the organization in the past 30 days.
**Attacker's Goals**
Bypass security filters and deliver malicious content to users
* Deploy malicious attachments through emails to compromise systems, gain unauthorized access, or facilitate cyber threats.
**Investigative actions**
* Carefully analyze attachments for any indications of suspicious or malicious behavior.
* Scrutinize the attachments for any suspicious indications.
* Confirm whether the attachments were successfully delivered to the recipient's mailbox.
* If the attachments were delivered successfully, verify whether the recipient downloaded them.
Attachment(s) with a potentially malicious MIME type that is unusual for the recipient
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------------------------- |
| ATT\&CK Tactic | Defense Evasion (TA0005), Execution (TA0002) |
| ATT\&CK Technique | Masquerading: Masquerade File Type (T1036.008), User Execution (T1204) |
| Severity | Informational |
**Description**
At least one attachment with a potentially malicious file mime-type was received in an email for the first time for the recipient in the past 30 days.
**Attacker's Goals**
Bypass security filters and deliver malicious content to users
* Deploy malicious attachments through emails to compromise systems, gain unauthorized access, or facilitate cyber threats.
**Investigative actions**
* Carefully analyze attachments for any indications of suspicious or malicious behavior.
* Scrutinize the attachments for any suspicious indications.
* Confirm whether the attachments were successfully delivered to the recipient's mailbox.
* If the attachments were delivered successfully, verify whether the recipient downloaded them.
---
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