Open Redirect: Club-OS

 1name: "Open Redirect: Club-OS"
 2description: |
 3    Message contains use of the Club-OS 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 == "club-os.com"
10      and strings.icontains(.href_url.path, 'click')
11      and strings.icontains(.href_url.query_params, 'target=')
12      // negate hash lookup targets (not actor controlled)
13      and not (
14        regex.icontains(.href_url.query_params, 'target=[a-f0-9]{40}(?:$|&)')
15        and strings.icontains(.href_url.query_params, '&hashLookup=true')
16      )
17  )
18  and (
19    not profile.by_sender().solicited
20    or (
21      profile.by_sender().any_messages_malicious_or_spam
22      and not profile.by_sender().any_false_positives
23    )
24  )
25
26  // negate highly trusted sender domains unless they fail DMARC authentication
27  and (
28    (
29      sender.email.domain.root_domain in $high_trust_sender_root_domains
30      and not headers.auth_summary.dmarc.pass
31    )
32    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
33  )  
34attack_types:
35  - "Credential Phishing"
36  - "Malware/Ransomware"
37tactics_and_techniques:
38  - "Open redirect"
39detection_methods:
40  - "Sender analysis"
41  - "URL analysis"
42id: "c6286914-059d-5879-8f17-b923304cb628"