Open redirect: mail.spiceworks.com

 1name: "Open redirect: mail.spiceworks.com"
 2description: |
 3    Message contains use of the mail.spiceworks.com 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.domain == "mail.spiceworks.com"
10          and strings.icontains(.href_url.query_params,
11                                '_externalContentRedirect'
12          )
13          and not regex.icontains(.href_url.query_params,
14                                  '_externalContentRedirect=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*spiceworks\.com(?:\&|\/|$|%2f)'
15          )
16  )
17  and not sender.email.domain.root_domain == "spiceworks.com"
18  
19  // negate highly trusted sender domains unless they fail DMARC authentication
20  and (
21    (
22      sender.email.domain.root_domain in $high_trust_sender_root_domains
23      and not headers.auth_summary.dmarc.pass
24    )
25    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
26  )  
27attack_types:
28  - "Credential Phishing"
29  - "Malware/Ransomware"
30tactics_and_techniques:
31  - "Open redirect"
32detection_methods:
33  - "Sender analysis"
34  - "URL analysis"
35id: "eb97defd-e636-56d9-b2de-c5e41947d7e5"