Brand impersonation: Gusto

 1name: "Brand impersonation: Gusto"
 2description: |
 3    Impersonation of Gusto, a cloud-based payroll management company.
 4type: "rule"
 5severity: "medium"
 6source: |
 7  type.inbound
 8  and (
 9    strings.ilike(sender.display_name, '*gusto*')
10    or strings.ilevenshtein(sender.display_name, 'gusto') <= 1
11    or strings.ilike(sender.email.domain.domain, '*gusto*')
12  )
13  and any(ml.logo_detect(beta.message_screenshot()).brands,
14          .name == "Gusto" and .confidence in ("medium", "high")
15  )
16  and sender.email.domain.root_domain !~ 'gusto.com'
17
18  and not profile.by_sender().solicited
19
20  // negate highly trusted sender domains unless they fail DMARC authentication
21  and (
22    (
23      sender.email.domain.root_domain in $high_trust_sender_root_domains
24      and not headers.auth_summary.dmarc.pass
25    )
26    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
27  )  
28
29attack_types:
30  - "Credential Phishing"
31tactics_and_techniques:
32  - "Impersonation: Brand"
33  - "Lookalike domain"
34  - "Social engineering"
35detection_methods:
36  - "Computer Vision"
37  - "Content analysis"
38  - "Header analysis"
39  - "Sender analysis"
40id: "54025c1c-34bc-5cbf-97b8-d544806fc587"