Open Redirect: amaterasu-for-website-5.com

 1name: "Open Redirect: amaterasu-for-website-5.com"
 2description: |
 3  Detects messages containing amaterasu-for-website-5.com redirect links that use the url
 4  parameter to redirect users to malicious sites. This has been observed in phishing campaigns.  
 5type: "rule"
 6severity: "medium"
 7source: |
 8  type.inbound
 9  and any(body.links,
10          // Look for website-5 URLs
11          .href_url.domain.domain == "api.amaterasu-for-website-5.com"
12          and strings.icontains(.href_url.query_params, 'url=')
13          // Make sure it's not redirecting back to website-5.com domains
14          and not regex.icontains(.href_url.query_params, 'url=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*website-5\.com(?:\&|\/|$|%2f)')
15  )
16  // Exclude legitimate website-5 domains as senders
17  and not sender.email.domain.root_domain == "website-5.com"
18  and not sender.email.domain.root_domain == "amaterasu-for-website-5.com"
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  )  
28attack_types:
29  - "Credential Phishing"
30  - "Malware/Ransomware"
31tactics_and_techniques:
32  - "Open redirect"
33detection_methods:
34  - "Sender analysis"
35  - "URL analysis"
36id: "d31f7cb8-1b75-53ef-b466-7d677392660b"