Open Redirect: xfinity.com

 1name: "Open Redirect: xfinity.com"
 2description: |
 3    Message contains use of the xfinity.com 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 == "xfinity.com"
10            and strings.icontains(.href_url.path, "/learn/cima/login")
11            and strings.icontains(.href_url.query_params, "referer=")
12            and not regex.icontains(.href_url.query_params,
13                                    'referer=(?:https?)?(?:(?:%3a|\:)?(?:\/|%2f){2})?xfinity\.com+'
14            )
15    )
16    and not sender.email.domain.root_domain in ("xfinity.com", "comcast.net")
17    and (
18    not profile.by_sender().solicited
19    or (
20        profile.by_sender().any_messages_malicious_or_spam
21        and not profile.by_sender().any_false_positives
22    )
23    )
24
25    // negate highly trusted sender domains unless they fail DMARC authentication
26    and (
27    (
28        sender.email.domain.root_domain in $high_trust_sender_root_domains
29        and not headers.auth_summary.dmarc.pass
30    )
31    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
32    )    
33attack_types:
34  - "Credential Phishing"
35  - "Malware/Ransomware"
36tactics_and_techniques:
37  - "Open redirect"
38detection_methods:
39  - "Sender analysis"
40  - "URL analysis"
41id: "7b9012fa-0f14-57d5-b729-cb3b84565c47"