Detection rules › Sublime MQL
Open redirect: emp.eduyield.com
Message contains use of the eduyield redirect which chains google amp. 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
| Message attribute |
|---|
| body |
| body.links (collection) |
| headers.auth_summary |
| sender.email |
| type |
Rule body MQL
type.inbound
and any(body.links,
.href_url.domain.domain == "emp.eduyield.com"
// the redirect field
and strings.icontains(.href_url.query_params, "&dest=")
and regex.icontains(.href_url.query_params,
'&dest=(?:https?)?(?:(?:%3a|\:)?(?:\/|%2f){2})?google\.com[^\&]*\/+amp\/+(s\/+)?'
)
)
and (
not profile.by_sender().solicited
or (
profile.by_sender().any_messages_malicious_or_spam
and not profile.by_sender().any_messages_benign
)
)
// 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 eduyield redirect which chains google amp. This has been exploited in the wild.
- inbound message
any of
body.linkswhere all hold:- .href_url.domain.domain is 'emp.eduyield.com'
- .href_url.query_params contains '&dest='
- .href_url.query_params matches '&dest=(?:https?)?(?:(?:%3a|\\:)?(?:\\/|%2f){2})?google\\.com[^\\&]*\\/+amp\\/+(s\\/+)?'
any of:
not:
- profile.by_sender().solicited
all of:
- profile.by_sender().any_messages_malicious_or_spam
not:
- profile.by_sender().any_messages_benign
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.domain, body.links[].href_url.query_params, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: profile.by_sender, regex.icontains, strings.icontains. Reference lists: $high_trust_sender_root_domains.
Indicators matched (3)
| Field | Match | Value |
|---|---|---|
body.links[].href_url.domain.domain | equals | emp.eduyield.com |
strings.icontains | substring | &dest= |
regex.icontains | regex | &dest=(?:https?)?(?:(?:%3a|\:)?(?:\/|%2f){2})?google\.com[^\&]*\/+amp\/+(s\/+)? |