Brand Impersonation: DocSend

 1name: "Brand Impersonation: DocSend"
 2description: |
 3    Attack impersonating DocSend.
 4references:
 5  - "https://docsend.com"
 6type: "rule"
 7severity: "high"
 8source: |
 9  type.inbound
10  and (
11    sender.display_name =~ 'DocSend'
12    or strings.ilevenshtein(sender.display_name, 'DocSend') <= 1
13    or strings.icontains(sender.email.domain.domain, '*docsend*')
14  )
15  and sender.email.domain.root_domain not in~ ('docsend.com')
16  and sender.email.email not in $recipient_emails
17  
18  // negate highly trusted sender domains unless they fail DMARC authentication
19  and (
20    (
21      sender.email.domain.root_domain in $high_trust_sender_root_domains
22      and not headers.auth_summary.dmarc.pass
23    )
24    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
25  )  
26attack_types:
27  - "Credential Phishing"
28tactics_and_techniques:
29  - "Impersonation: Brand"
30  - "Lookalike domain"
31  - "Social engineering"
32detection_methods:
33  - "Header analysis"
34  - "Sender analysis"
35id: "cd9a3f7a-bda2-5cf9-9a0f-8acef23711a3"