Detection rules › Sublime MQL
Open redirect: fenc.com
Message contains use of the fenc.com open 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
| Message attribute |
|---|
| body |
| body.links (collection) |
| headers.auth_summary |
| sender.email |
| type |
Rule body MQL
type.inbound
and any(body.links,
.href_url.domain.root_domain == "fenc.com"
and .href_url.path =~ "/redirector.aspx"
and regex.icontains(.href_url.query_params,
'y=(?:https?|(?:\/|%2f)(?:\/|%2f))'
)
and not regex.icontains(.href_url.query_params, 'y=[^\&]*fenc\.com')
)
and not sender.email.domain.root_domain == "fenc.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 fenc.com open redirect. This has been exploited in the wild.
- inbound message
any of
body.linkswhere all hold:- .href_url.domain.root_domain is 'fenc.com'
- .href_url.path is '/redirector.aspx'
- .href_url.query_params matches 'y=(?:https?|(?:\\/|%2f)(?:\\/|%2f))'
not:
- .href_url.query_params matches 'y=[^\\&]*fenc\\.com'
not:
- sender.email.domain.root_domain is 'fenc.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.path, body.links[].href_url.query_params, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: regex.icontains. Reference lists: $high_trust_sender_root_domains.
Indicators matched (5)
| Field | Match | Value |
|---|---|---|
body.links[].href_url.domain.root_domain | equals | fenc.com |
body.links[].href_url.path | equals | /redirector.aspx |
regex.icontains | regex | y=(?:https?|(?:\/|%2f)(?:\/|%2f)) |
regex.icontains | regex | y=[^\&]*fenc\.com |
sender.email.domain.root_domain | equals | fenc.com |