Open Redirect: ExacTag

 1name: "Open Redirect: ExacTag"
 2description: |
 3    Message contains use of the ExacTag open redirect. This has been exploited in the wild.
 4type: "rule"
 5severity: "medium"
 6source: |
 7  type.inbound
 8  and any(body.links,
 9      .href_url.domain.root_domain == "exactag.com"
10      and strings.icontains(.href_url.path, 'ai.aspx')
11      and strings.icontains(.href_url.query_params, 'url=')
12  )
13  and (
14    not profile.by_sender().solicited
15    or (
16      profile.by_sender().any_messages_malicious_or_spam
17      and not profile.by_sender().any_false_positives
18    )
19  )
20
21  // negate highly trusted sender domains unless they fail DMARC authentication
22  and (
23    (
24      sender.email.domain.root_domain in $high_trust_sender_root_domains
25      and not headers.auth_summary.dmarc.pass
26    )
27    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
28  )  
29attack_types:
30  - "Credential Phishing"
31  - "Malware/Ransomware"
32tactics_and_techniques:
33  - "Open redirect"
34detection_methods:
35  - "Sender analysis"
36  - "URL analysis"
37id: "5e40ea99-3290-5792-a618-bb77ae282a90"