Detection rules › Sublime MQL
Link: CVE-2024-21413 Microsoft Outlook Remote Code Execution Vulnerability
This rule detects messages containing links exploiting CVE-2024-21413, which can lead to RCE. Successful exploitation can bypass built-in Outlook protections for malicious links embedded in messages by using the file:// protocol and an exclamation mark to URLs pointing to attacker-controlled servers."
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Malware/Ransomware |
| Tactics and techniques | Evasion, Exploit |
Event coverage
| Message attribute |
|---|
| body |
| body.links (collection) |
| type |
Rule body MQL
type.inbound
and any(body.links,
.href_url.scheme == "file"
and regex.icontains(.href_url.url, '\.[a-z]{2,4}(\.[a-z]{2,4})?!')
)
Detection logic
Scope: inbound message.
This rule detects messages containing links exploiting CVE-2024-21413, which can lead to RCE. Successful exploitation can bypass built-in Outlook protections for malicious links embedded in messages by using the file:// protocol and an exclamation mark to URLs pointing to attacker-controlled servers."
- inbound message
any of
body.linkswhere all hold:- .href_url.scheme is 'file'
- .href_url.url matches '\\.[a-z]{2,4}(\\.[a-z]{2,4})?!'
Inspects: body.links, body.links[].href_url.scheme, body.links[].href_url.url, type.inbound. Sensors: regex.icontains.
Indicators matched (2)
| Field | Match | Value |
|---|---|---|
body.links[].href_url.scheme | equals | file |
regex.icontains | regex | \.[a-z]{2,4}(\.[a-z]{2,4})?! |