Detection rules › Sublime MQL
Attachment: Embedded VBScript in MHT file
MHT files can be used to run VBScript, which can run malicious code.
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Malware/Ransomware |
| Tactics and techniques | Evasion, Scripting |
Event coverage
| Message attribute |
|---|
| attachments (collection) |
| type |
Rule body MQL
type.inbound
and any(attachments,
(
.file_extension =~ "mht"
or .file_extension in~ $file_extensions_common_archives
)
// ensure there's an mht file (if it's in an archive)
and any(file.explode(.), .file_extension =~ "mht")
and any(file.explode(.),
any(.scan.html.scripts, .language == "VBScript")
)
)
Detection logic
Scope: inbound message.
MHT files can be used to run VBScript, which can run malicious code.
- inbound message
any of
attachmentswhere all hold:any of:
- .file_extension is 'mht'
- .file_extension in $file_extensions_common_archives
any of
file.explode(.)where:- .file_extension is 'mht'
any of
file.explode(.)where:any of
.scan.html.scriptswhere:- .language is 'VBScript'
Inspects: attachments[].file_extension, type.inbound. Sensors: file.explode. Reference lists: $file_extensions_common_archives.
Indicators matched (3)
| Field | Match | Value |
|---|---|---|
attachments[].file_extension | equals | mht |
file.explode(attachments[])[].file_extension | equals | mht |
file.explode(attachments[])[].scan.html.scripts[].language | equals | VBScript |