Medium Severity

Spam: New link domain (<=10d) and emojis

Description

Detects spam from freemail senders, where the linked domain is less than 10 days old and emojis present.

References

No references.

Sublime Security
Created Aug 25th, 2023 • Last updated Apr 25th, 2024
Source
type.inbound

// sender is a freemail
and sender.email.domain.root_domain in $free_email_providers

// linked domain is less than 10 days old
and any(body.links, network.whois(.href_url.domain).days_old < 10)

// has an emoji in the subject or body
and (
  regex.contains(body.plain.raw,
                 '[\x{1F300}-\x{1F5FF}\x{1F600}-\x{1F64F}\x{1F680}-\x{1F6FF}\x{1F700}-\x{1F77F}\x{1F780}-\x{1F7FF}\x{1F900}-\x{1F9FF}\x{2600}-\x{26FF}\x{2700}-\x{27BF}\x{2300}-\x{23FF}]'
  )
  or regex.contains(subject.subject,
                    '[\x{1F300}-\x{1F5FF}\x{1F600}-\x{1F64F}\x{1F680}-\x{1F6FF}\x{1F700}-\x{1F77F}\x{1F780}-\x{1F7FF}\x{1F900}-\x{1F9FF}\x{2600}-\x{26FF}\x{2700}-\x{27BF}\x{2300}-\x{23FF}]'
  )
)
and (
  profile.by_sender().prevalence in ("new", "outlier")
  or (
    profile.by_sender().any_messages_malicious_or_spam
    and not profile.by_sender().any_false_positives
  )
)
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