sublimehighRule

Attachment: PDF with View RFP Document lure with external link

Detects inbound emails containing a PDF attachment that references a 'VIEW RFP DOCUMENT' lure and embeds a URL pointing to a domain that differs from the sender's domain, a pattern consistent with document-based social engineering used to redirect recipients to attacker-controlled infrastructure.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598

initial-access

Detection Query

type.inbound
and any(filter(attachments, .file_type == "pdf"),
        any(file.explode(.),
            any(.scan.strings.strings, . =~ 'VIEW RFP DOCUMENT')
        )
        and any(file.explode(.),
                length(filter(.scan.url.urls,
                              .scheme != "mailto"
                              and .domain.domain != sender.email.domain.domain
                       )
                ) > 0
        )
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Raw Content

name: "Attachment: PDF with View RFP Document lure with external link"
description: "Detects inbound emails containing a PDF attachment that references a 'VIEW RFP DOCUMENT' lure and embeds a URL pointing to a domain that differs from the sender's domain, a pattern consistent with document-based social engineering used to redirect recipients to attacker-controlled infrastructure."
type: "rule"
severity: "high"
source: |
  type.inbound
  and any(filter(attachments, .file_type == "pdf"),
          any(file.explode(.),
              any(.scan.strings.strings, . =~ 'VIEW RFP DOCUMENT')
          )
          and any(file.explode(.),
                  length(filter(.scan.url.urls,
                                .scheme != "mailto"
                                and .domain.domain != sender.email.domain.domain
                         )
                  ) > 0
          )
  )
attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "PDF"
  - "Social engineering"
detection_methods:
  - "File analysis"
  - "URL analysis"
  - "Content analysis"
id: "ad4bcc06-059d-5770-8b9b-b7560472d965"