Link: Possible Intuit link abuse

 1name: "Link: Possible Intuit link abuse"
 2description: "Detects messages linking to Intuit notification domains from non-Intuit senders, combined with credential harvesting language and file sharing themes"
 3type: "rule"
 4severity: "medium"
 5source: |
 6  type.inbound
 7  // look for links to links.notification.intuit.com but the sender is not from quickbooks/intuit
 8  and any(body.current_thread.links,
 9          .href_url.domain.domain == "links.notification.intuit.com"
10  )
11  and not sender.email.domain.root_domain in ("quickbooks.com", "intuit.com")
12  and not (
13    any(headers.domains, .root_domain in ("quickbooks.com", "intuit.com"))
14    // Intuit owns Mandrill, so its MTAs show up under intuit.com - transport, not sender
15    and headers.return_path.domain.root_domain not in ("mandrillapp.com")
16  )
17  and length(body.current_thread.text) < 1750  
18tags:
19 - "Attack surface reduction"
20attack_types:
21  - "Credential Phishing"
22tactics_and_techniques:
23  - "Impersonation: Brand"
24  - "Social engineering"
25detection_methods:
26  - "URL analysis"
27  - "Natural Language Understanding"
28  - "Content analysis"
29  - "Header analysis"
30id: "cd15cc34-76b3-5993-bade-053e05b2ad48"