Description

Detects messages sent from Arketa's notification address (no-reply@notifications.arketa.co) that has been abused to deliver callback scam content. The rule flags messages where an NLU classifier identifies callback scam intent, or where the body references well-known brands (e.g., McAfee, Norton, PayPal, eBay, Best Buy) alongside scam-related keywords (purchase, invoice, refund, cancel, etc.) and includes a phone number formatted to evade detection through character substitution or spacing tricks.

References

No references.

Sublime Security
Created Aug 19th, 2026 • Last updated Aug 19th, 2026
Source
type.inbound
and sender.email.email == "no-reply@notifications.arketa.co"
and (
  any(ml.nlu_classifier(body.current_thread.text).intents,
      .name == "callback_scam" and .confidence != "low"
  )
  or (
    regex.icontains(body.current_thread.text,
                    (
                      "mcafee|n[o0]rt[o0]n|geek.{0,5}squad|paypal|ebay|symantec|best buy|lifel[o0]ck"
                    )
    )
    and (
      3 of (
        strings.ilike(body.current_thread.text, '*purchase*'),
        strings.ilike(body.current_thread.text, '*payment*'),
        strings.ilike(body.current_thread.text, '*transaction*'),
        strings.ilike(body.current_thread.text, '*subscription*'),
        strings.ilike(body.current_thread.text, '*antivirus*'),
        strings.ilike(body.current_thread.text, '*order*'),
        strings.ilike(body.current_thread.text, '*support*'),
        strings.ilike(body.current_thread.text, '*receipt*'),
        strings.ilike(body.current_thread.text, '*invoice*'),
        strings.ilike(body.current_thread.text, '*call*'),
        strings.ilike(body.current_thread.text, '*cancel*'),
        strings.ilike(body.current_thread.text, '*renew*'),
        strings.ilike(body.current_thread.text, '*refund*'),
        strings.ilike(body.current_thread.text, '*host key*')
      )
    )
    // phone number regex
    and any([body.current_thread.text, subject.subject],
            regex.icontains(strings.replace_confusables(.),
                            '\+?([ilo0-9]{1}.)?\(?[ilo0-9]{3}?\)?.[ilo0-9]{3}.?[ilo0-9]{4}',
                            '\+?([ilo0-9]{1,2})?\s?\(?\d{3}\)?[\s\.\-⋅]{0,5}[ilo0-9]{3}[\s\.\-⋅]{0,5}[ilo0-9]{4}',
                            '[\+\x{FF0B}]?(?:\p{N}[^\p{N}]{0,3}){10,11}'
            )
    )
  )
)
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