sublimehighRule

Attachment: Malformed OLE file

Attached OLE file (typically a Microsoft Office document) is malformed, possibly to evade traditional scanners and filters.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598 T1204.002 T1486 T1036 T1027

defense-evasion

Detection Query

type.inbound
and any(attachments,
        .file_extension in $file_extensions_macros
        and any(file.explode(.),
                any(.scan.yara.matches, .name == "MALFORMED_OLE_HEADER")
        )
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

References

https://x.com/anyrun_app/status/1861024182210900357

Raw Content

name: "Attachment: Malformed OLE file"
description: |
  Attached OLE file (typically a Microsoft Office document) is malformed, possibly to evade traditional scanners and filters.
references:
  - "https://x.com/anyrun_app/status/1861024182210900357"
type: "rule"
severity: "high"
source: |
  type.inbound
  and any(attachments,
          .file_extension in $file_extensions_macros
          and any(file.explode(.),
                  any(.scan.yara.matches, .name == "MALFORMED_OLE_HEADER")
          )
  )
attack_types:
  - "Credential Phishing"
  - "Malware/Ransomware"
tactics_and_techniques:
  - "Evasion"
detection_methods:
  - "File analysis"
  - "YARA"
id: "5aadc68f-9a67-5fd0-a825-3d7e1c5bfcb3"