Open redirect: Medium

 1name: "Open redirect: Medium"
 2description: |
 3    Message contains use of the Medium 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 == "medium.com"
10          and strings.icontains(.href_url.path, "/global-identity-2")
11          and strings.icontains(.href_url.query_params, "redirectUrl=")
12          // negate redirects to medium.com
13          and not regex.icontains(.href_url.query_params,
14                                  'redirectUrl=(?:(?:https?(?:%3a|:))?(?:%2f|\/){2})?(?:[a-z0-9]+\.)*medium\.com'
15          )
16  )
17  
18  // negate highly trusted sender domains unless they fail DMARC authentication
19  and not (
20    sender.email.domain.root_domain in $high_trust_sender_root_domains
21    and coalesce(headers.auth_summary.dmarc.pass, false)
22  )  
23attack_types:
24  - "Credential Phishing"
25  - "Malware/Ransomware"
26tactics_and_techniques:
27  - "Open redirect"
28detection_methods:
29  - "Sender analysis"
30  - "URL analysis"
31id: "18c6aa1b-dee4-5ca6-a3bd-706cc7368e28"