Detection rules › Sublime MQL
Attachment: JavaScript file with suspicious base64-encoded executable
JavaScript attachment or compressed JavaScript file containing a base64 encoded executable.
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 in~ $file_extensions_common_archives
or .file_extension in ("js", "jar")
)
and any(file.explode(.),
(
(
.file_extension in ("js", "jar")
or any(.flavors.yara, . == "javascript_file")
)
and any(.flavors.yara, . == 'base64_pe')
)
)
)
Detection logic
Scope: inbound message.
JavaScript attachment or compressed JavaScript file containing a base64 encoded executable.
- inbound message
any of
attachmentswhere all hold:any of:
- .file_extension in $file_extensions_common_archives
- .file_extension in ('js', 'jar')
any of
file.explode(.)where all hold:any of:
- .file_extension in ('js', 'jar')
any of
.flavors.yarawhere:- . is 'javascript_file'
any of
.flavors.yarawhere:- . is 'base64_pe'
Inspects: attachments[].file_extension, type.inbound. Sensors: file.explode. Reference lists: $file_extensions_common_archives.
Indicators matched (6)
| Field | Match | Value |
|---|---|---|
attachments[].file_extension | member | js |
attachments[].file_extension | member | jar |
file.explode(attachments[])[].file_extension | member | js |
file.explode(attachments[])[].file_extension | member | jar |
file.explode(attachments[])[].flavors.yara[] | equals | javascript_file |
file.explode(attachments[])[].flavors.yara[] | equals | base64_pe |