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 (
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"
28  - "Malware/Ransomware"
29tactics_and_techniques:
30  - "Open redirect"
31detection_methods:
32  - "Sender analysis"
33  - "URL analysis"
34id: "18c6aa1b-dee4-5ca6-a3bd-706cc7368e28"