Detection rules › Sublime MQL
Attachment: Macro files containing MHT content
Detects macro-enabled files that contain embedded MHT (MIME HTML) content, which is commonly used to hide malicious code through file format manipulation.
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Malware/Ransomware, Credential Phishing |
| Tactics and techniques | Evasion, Macros, Scripting |
Event coverage
| Message attribute |
|---|
| attachments (collection) |
| type |
Rule body MQL
type.inbound
and any(attachments,
.file_extension in $file_extensions_macros
and any(file.explode(.),
.file_extension == "mht"
and not .flavors.mime == "message/rfc822"
)
)
Detection logic
Scope: inbound message.
Detects macro-enabled files that contain embedded MHT (MIME HTML) content, which is commonly used to hide malicious code through file format manipulation.
- inbound message
any of
attachmentswhere all hold:- .file_extension in $file_extensions_macros
any of
file.explode(.)where all hold:- .file_extension is 'mht'
not:
- .flavors.mime is 'message/rfc822'
Inspects: attachments[].file_extension, type.inbound. Sensors: file.explode. Reference lists: $file_extensions_macros.
Indicators matched (2)
| Field | Match | Value |
|---|---|---|
file.explode(attachments[])[].file_extension | equals | mht |
file.explode(attachments[])[].flavors.mime | equals | message/rfc822 |