sublimemediumRule

Attachment: PDF with split QR code

Detects PDF attachments containing split QR codes positioned close together, a technique used to evade detection while maintaining QR code functionality for credential theft.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598 T1036 T1027

defense-evasion

Detection Query

type.inbound
and any(filter(attachments, .file_type == "pdf"),
        any(file.explode(.),
            any(.scan.yara.matches,
                // yara rules match on "split" QR codes that are 290x290, 300x300, 370x370 and placed close to eachtoher in the PDF
                strings.istarts_with(.name, 'Phishing_PDF_Split_QR_Code_Pair')
            )
        )
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Raw Content

name: "Attachment: PDF with split QR code"
description: "Detects PDF attachments containing split QR codes positioned close together, a technique used to evade detection while maintaining QR code functionality for credential theft."
type: "rule"
severity: "medium"
source: |
  type.inbound
  and any(filter(attachments, .file_type == "pdf"),
          any(file.explode(.),
              any(.scan.yara.matches,
                  // yara rules match on "split" QR codes that are 290x290, 300x300, 370x370 and placed close to eachtoher in the PDF
                  strings.istarts_with(.name, 'Phishing_PDF_Split_QR_Code_Pair')
              )
          )
  )
attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "Evasion"
  - "PDF"
  - "QR code"
detection_methods:
  - "File analysis"
  - "YARA"
  - "QR code analysis"
id: "b6889ea1-522b-5410-8ccf-ce261fa1fd5f"