Detection rules › Sublime MQL
Attachment with encrypted zip (unsolicited)
Recursively scans files and archives to detect encrypted zip files.
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Malware/Ransomware |
| Tactics and techniques | Evasion, Encryption |
Event coverage
| Message attribute |
|---|
| attachments (collection) |
| type |
Rule body MQL
type.inbound
and any(attachments,
(.file_type == "zip" or .file_extension == "zip")
and any(file.explode(.), any(.flavors.yara, . == 'encrypted_zip'))
)
and (
not profile.by_sender().solicited
or (
profile.by_sender().any_messages_malicious_or_spam
and not profile.by_sender().any_messages_benign
)
)
and not profile.by_sender().prevalence == "common"
Detection logic
Scope: inbound message.
Recursively scans files and archives to detect encrypted zip files.
- inbound message
any of
attachmentswhere all hold:any of:
- .file_type is 'zip'
- .file_extension is 'zip'
any of
file.explode(.)where:any of
.flavors.yarawhere:- . is 'encrypted_zip'
any of:
not:
- profile.by_sender().solicited
all of:
- profile.by_sender().any_messages_malicious_or_spam
not:
- profile.by_sender().any_messages_benign
not:
- profile.by_sender().prevalence is 'common'
Inspects: attachments[].file_extension, attachments[].file_type, type.inbound. Sensors: file.explode, profile.by_sender.
Indicators matched (3)
| Field | Match | Value |
|---|---|---|
attachments[].file_type | equals | zip |
attachments[].file_extension | equals | zip |
file.explode(attachments[])[].flavors.yara[] | equals | encrypted_zip |