Detection rules › Sublime MQL

Suspicious link to Looker Studio (lookerstudio.google.com) from a new and unsolicited sender

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

This rule detects messages containing links to lookerstudio with a non standard lookerstudio template from a new and unsolicited sender.

Threat classification

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

CategoryValues
Attack typesCredential Phishing
Tactics and techniquesEvasion, Social engineering

Event coverage

Rule body MQL

type.inbound
and length(body.current_thread.text) < 1000
and regex.icontains(body.current_thread.text,
                    '(shared.{0,30}with you|View Document)'
)
and any(body.links, .href_url.domain.domain == "lookerstudio.google.com")
and (
  profile.by_sender().prevalence in ("new", "outlier")
  and not profile.by_sender().solicited
)

// 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.

This rule detects messages containing links to lookerstudio with a non standard lookerstudio template from a new and unsolicited sender.

  1. inbound message
  2. length(body.current_thread.text) < 1000
  3. body.current_thread.text matches '(shared.{0,30}with you|View Document)'
  4. any of body.links where:
    • .href_url.domain.domain is 'lookerstudio.google.com'
  5. all of:
    • profile.by_sender().prevalence in ('new', 'outlier')
    • not:
      • profile.by_sender().solicited
  6. 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.current_thread.text, body.links, body.links[].href_url.domain.domain, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: profile.by_sender, regex.icontains. Reference lists: $high_trust_sender_root_domains.

Indicators matched (2)

FieldMatchValue
regex.icontainsregex(shared.{0,30}with you|View Document)
body.links[].href_url.domain.domainequalslookerstudio.google.com