Medium Severity
Service Abuse: Adobe Sign Notification From an Unsolicited Reply-To Address
Description
Identifies messages appearing to come from Adobe Sign signature notifications that contain a reply-to address not previously seen in organizational communications. This tactic exploits trust in legitimate Adobe services while attempting to establish unauthorized communication channels.
References
No references.
Sublime Security
Created Apr 30th, 2025 • Last updated Apr 30th, 2025
Feed Source
Sublime Core Feed
Source
type.inbound
// Legitimate Adobe Sign sending infratructure
and sender.email.email == "adobesign@adobesign.com"
and headers.auth_summary.spf.pass
and headers.auth_summary.dmarc.pass
and strings.icontains(subject.subject, 'signature requested')
//
// This rule makes use of a beta feature and is subject to change without notice
// using the beta feature in custom rules is not suggested until it has been formally released
//
// reply-to address has never sent an email to the org
and beta.profile.by_reply_to().prevalence == "new"
// reply-to email address has never been sent an email by the org
and not beta.profile.by_reply_to().solicited
// do not match if the reply_to address has been observed as a reply_to address
// of a message that has been classified as benign
and not beta.profile.by_reply_to().any_messages_benign
Playground
Test against your own EMLs or sample data.