sublimemediumRule

Service abuse: Postman reply-to mismatch with credential theft intent

Detects inbound messages sent from Postman.io where the reply-to address belongs to a different domain than the sender, combined with high or medium confidence credential theft intent detected in the message body. This technique leverages a legitimate service to deliver messages while redirecting replies to an attacker-controlled address.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598

initial-access

Detection Query

type.inbound
and sender.email.domain.root_domain == "postman.io"
and any(headers.reply_to,
        .email.domain.root_domain != sender.email.domain.root_domain
)
and any(ml.nlu_classifier(body.current_thread.text).intents,
        .name == "cred_theft" and .confidence != "low"
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Raw Content

name: "Service abuse: Postman reply-to mismatch with credential theft intent"
description: "Detects inbound messages sent from Postman.io where the reply-to address belongs to a different domain than the sender, combined with high or medium confidence credential theft intent detected in the message body. This technique leverages a legitimate service to deliver messages while redirecting replies to an attacker-controlled address."
type: "rule"
severity: "medium"
source: |
  type.inbound
  and sender.email.domain.root_domain == "postman.io"
  and any(headers.reply_to,
          .email.domain.root_domain != sender.email.domain.root_domain
  )
  and any(ml.nlu_classifier(body.current_thread.text).intents,
          .name == "cred_theft" and .confidence != "low"
  )
attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "Social engineering"
  - "Out of band pivot"
detection_methods:
  - "Sender analysis"
  - "Header analysis"
  - "Natural Language Understanding"
id: "d7177124-8e9f-5916-a3c5-45c22b34ce4f"