Detection rules › Sublime MQL
Open redirect: smartadserver.com
Message contains use of the smartadserver.com redirect. This has been exploited in the wild.
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Credential Phishing, Malware/Ransomware |
| Tactics and techniques | Open redirect |
Event coverage
Rule body MQL
type.inbound
// smartadserver is used in benign messages, however, they commonly have many links
// ensure messages contain less than 15 links to ensure higher fidelity matching of malicious messages
and length(body.links) < 15
and any(body.links,
.href_url.domain.root_domain == "smartadserver.com"
and strings.icontains(.href_url.query_params, 'go=')
and not regex.icontains(.href_url.query_params,
'go=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*smartadserver\.com(?:\&|\/|$|%2f)'
)
)
// remove uses that originate from smartadserver.com
and not any(headers.domains, .root_domain == "smartadserver.com")
// negate highly trusted sender domains unless they fail DMARC authentication
and (
(
sender.email.domain.root_domain in $high_trust_sender_root_domains
and not headers.auth_summary.dmarc.pass
)
or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)
Detection logic
Scope: inbound message.
Message contains use of the smartadserver.com redirect. This has been exploited in the wild.
- inbound message
- length(body.links) < 15
any of
body.linkswhere all hold:- .href_url.domain.root_domain is 'smartadserver.com'
- .href_url.query_params contains 'go='
not:
- .href_url.query_params matches 'go=(?:https?(?:%3a|:))?(?:%2f|\\/){2}[^&]*smartadserver\\.com(?:\\&|\\/|$|%2f)'
not:
any of
headers.domainswhere:- .root_domain is 'smartadserver.com'
any of:
all of:
- sender.email.domain.root_domain in $high_trust_sender_root_domains
not:
- headers.auth_summary.dmarc.pass
- sender.email.domain.root_domain not in $high_trust_sender_root_domains
Inspects: body.links, body.links[].href_url.domain.root_domain, body.links[].href_url.query_params, headers.auth_summary.dmarc.pass, headers.domains, headers.domains[].root_domain, sender.email.domain.root_domain, type.inbound. Sensors: regex.icontains, strings.icontains. Reference lists: $high_trust_sender_root_domains.
Indicators matched (4)
| Field | Match | Value |
|---|---|---|
body.links[].href_url.domain.root_domain | equals | smartadserver.com |
strings.icontains | substring | go= |
regex.icontains | regex | go=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*smartadserver\.com(?:\&|\/|$|%2f) |
headers.domains[].root_domain | equals | smartadserver.com |