High Severity

Service abuse: Mimecast URL with excessive path length

Description

Detects messages containing the second stage Mimecast redirect URL with unusually long paths, potentially indicating abuse of the Mimecast URL redirection service to obfuscate malicious destinations.

References

No references.

Sublime Security
Created Apr 8th, 2026 • Last updated Apr 8th, 2026
Source
type.inbound
and any(filter(body.links,
               strings.icontains(.href_url.domain.root_domain, "mimecast")
               and strings.starts_with(.href_url.path, "/r/")
        ),
        length(.href_url.path) > 2000
)
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