• Sublime Core Feed
High Severity

Attachment: Calendar invite with suspicious link leading to an open redirect

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Description

Calendar invite contains a link to either a free file host or free subdomain host, and the resulting webpage contains another link to an open redirect.

References

No references.

Sublime Security
Created Mar 26th, 2024 • Last updated Mar 26th, 2024
Feed Source
Sublime Core Feed
Source
GitHub
type.inbound
and any(attachments,
        (
          .file_extension == "ics"
          or .content_type in ("application/ics", "text/calendar")
        )
        and any(file.explode(.),
                any(.scan.url.urls,
                    (
                      .domain.domain in $free_file_hosts
                      or (
                        .domain.root_domain in $free_subdomain_hosts
                        and .domain.subdomain is not null
                        and not (
                          strings.ends_with(.url, "jpeg")
                          or strings.ends_with(.url, "png")
                        )
                        and .domain.subdomain != "www"
                      )
                    )
                    and any(beta.linkanalysis(.).final_dom.links,
                            any(.href_url.rewrite.encoders,
                                strings.icontains(., "open_redirect")
                            )
                    )
                )
        )
)
// negate highly trusted sender domains unless they fail DMARC authentication
and (
  (
    sender.email.domain.root_domain in $high_trust_sender_root_domains
    and (
      any(distinct(headers.hops, .authentication_results.dmarc is not null),
          strings.ilike(.authentication_results.dmarc, "*fail")
      )
    )
  )
  or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)
and (
  not profile.by_sender().solicited
  or (
    profile.by_sender().any_messages_malicious_or_spam
    and not profile.by_sender().any_false_positives
  )
)
and not profile.by_sender().any_false_positives

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