Detection rules › Sublime MQL

Open redirect: Klaviyo

Severity
medium
Type
rule
Source
github.com/sublime-security/sublime-rules

Message contains use of the Klaviyo (kmail-lists.com) open redirect, but the link display text does not match known permutations. This has been exploited in the wild.

Threat classification

Sublime's own taxonomy (not MITRE ATT&CK).

CategoryValues
Attack typesCredential Phishing, Spam
Tactics and techniquesEvasion, Impersonation: Brand, Open redirect, Social engineering

Event coverage

Rule body MQL

type.inbound
and any(body.links,
        .href_url.domain.domain == 'manage.kmail-lists.com'
        and .href_url.path =~ '/subscriptions/subscribe/update'
        and strings.icontains(.href_url.query_params, 'r=')
        and not strings.ilike(.display_text, "*subscribe*", "*manage*")
)

Detection logic

Scope: inbound message.

Message contains use of the Klaviyo (kmail-lists.com) open redirect, but the link display text does not match known permutations. This has been exploited in the wild.

  1. inbound message
  2. any of body.links where all hold:
    • .href_url.domain.domain is 'manage.kmail-lists.com'
    • .href_url.path is '/subscriptions/subscribe/update'
    • .href_url.query_params contains 'r='
    • not:
      • .display_text matches any of 2 patterns
        • *subscribe*
        • *manage*

Inspects: body.links, body.links[].display_text, body.links[].href_url.domain.domain, body.links[].href_url.path, body.links[].href_url.query_params, type.inbound. Sensors: strings.icontains, strings.ilike.

Indicators matched (5)

FieldMatchValue
body.links[].href_url.domain.domainequalsmanage.kmail-lists.com
body.links[].href_url.pathequals/subscriptions/subscribe/update
strings.icontainssubstringr=
strings.ilikesubstring*subscribe*
strings.ilikesubstring*manage*