Detection rules › Sublime MQL
Attachment: Filename containing Unicode right-to-left override character
Recursively identifies attachments that attempt to conceal their true file extension by using right-to-left override characters
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Malware/Ransomware |
| Tactics and techniques | Evasion |
Event coverage
| Message attribute |
|---|
| attachments (collection) |
| type |
Rule body MQL
type.inbound
and any(attachments,
regex.icontains(.file_name, '\x{202E}', '\x{202D}')
or (
.file_extension in~ $file_extensions_common_archives
and any(file.explode(.),
regex.icontains(.file_name, '\x{202E}', '\x{202D}')
)
)
)
Detection logic
Scope: inbound message.
Recursively identifies attachments that attempt to conceal their true file extension by using right-to-left override characters
- inbound message
any of
attachmentswhere any holds:.file_name matches any of 2 patterns
\x{202E}\x{202D}
all of:
- .file_extension in $file_extensions_common_archives
any of
file.explode(.)where:.file_name matches any of 2 patterns
\x{202E}\x{202D}
Inspects: attachments[].file_extension, attachments[].file_name, type.inbound. Sensors: file.explode, regex.icontains. Reference lists: $file_extensions_common_archives.
Indicators matched (2)
| Field | Match | Value |
|---|---|---|
regex.icontains | regex | \x{202E} |
regex.icontains | regex | \x{202D} |