Brand Impersonation: Navan

 1name: "Brand Impersonation: Navan"
 2description: "Impersonation of the expense management provider Navan."
 3type: "rule"
 4severity: "medium"
 5source: |
 6  type.inbound
 7  and (
 8    regex.icontains(sender.display_name, '(?:The\s+)?\bNavan\b(?:\s+Team)?')
 9    or strings.ilike(sender.email.domain.domain, '*Navan*')
10  )
11  and (
12    any(ml.logo_detect(beta.message_screenshot()).brands,
13        .name == "Navan" and .confidence in ("medium", "high")
14    )
15    or (
16      regex.icontains(subject.subject,
17                      "(?:unrecognized|Unusual|suspicious|unknown) (?:log|sign).?[io]n attempt",
18                      "(?:important|urgent|attention|alert) account|accessed|[new|unrecognized|suspicious] location"
19      )
20      or any(ml.nlu_classifier(body.current_thread.text).entities,
21             .name == "urgency"
22      )
23      or any(ml.nlu_classifier(body.current_thread.text).intents,
24             .name in ("cred_theft", "steal_pii")
25      )
26    )
27  )
28  and sender.email.domain.root_domain not in~ ('navan.com')
29  
30  // negate highly trusted sender domains unless they fail DMARC authentication
31  and (
32    (
33      sender.email.domain.root_domain in $high_trust_sender_root_domains
34      and not headers.auth_summary.dmarc.pass
35    )
36    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
37  )
38  and (
39    not profile.by_sender().solicited
40    or (
41      profile.by_sender().any_messages_malicious_or_spam
42      and not profile.by_sender().any_false_positives
43    )
44  )
45  and not profile.by_sender().any_false_positives  
46
47attack_types:
48  - "Credential Phishing"
49tactics_and_techniques:
50  - "Impersonation: Brand"
51  - "Social engineering"
52  - "Spoofing"
53detection_methods:
54  - "Sender analysis"
55  - "Natural Language Understanding"
56  - "URL analysis"
57  - "Content analysis"
58id: "3573e9a8-0ab7-5693-8386-8c75c95659b2"