Impersonation: SAM/SBA federal registration

 1name: "Impersonation: SAM/SBA federal registration"
 2description: "Detects inbound messages impersonating SAM.gov or the Small Business Administration by matching sender display names against known spoofed naming patterns (e.g. sba-support, sam registration/renewal) or by identifying sam.gov references paired with an embedded 'renew entity' image lure. Legitimate senders from verified sba.gov, sam.gov, or other high-trust domains that pass DMARC authentication are excluded."
 3type: "rule"
 4severity: "high"
 5source: |
 6  type.inbound
 7  and (
 8    regex.icontains(sender.display_name,
 9                    '^sam(?:\.gov\b|\s(?:renew|compliance))',
10                    'final\ssam\.gov',
11                    '^sba[\s-]?(?:e[fd]|[\.,]gov)',
12                    '^sba[\s-](?:connect|invoice|admin|eidl)\b',
13                    '^sba[\s-]support[\s-]\w+'
14    )
15    or (
16      strings.icontains(body.current_thread.text, 'sam.gov')
17      and any(html.xpath(body.html, '//img/@src').nodes,
18              strings.icontains(.raw, 'sam%20renew%20entity')
19      )
20    )
21  )
22  and not (
23    sender.email.domain.root_domain in $high_trust_sender_root_domains
24    and coalesce(headers.auth_summary.dmarc.pass, false)
25  )  
26attack_types:
27  - "Credential Phishing"
28  - "BEC/Fraud"
29tactics_and_techniques:
30  - "Impersonation: Brand"
31  - "Social engineering"
32  - "Image as content"
33detection_methods:
34  - "Sender analysis"
35  - "Content analysis"
36  - "HTML analysis"
37  - "Header analysis"
38id: "057ad471-4564-584c-a700-bba6e0c6eea9"