sublimemediumRule

Attachment: Encrypted ZIP containing VHDX file

Detects ZIP attachments that are encrypted and contain VHDX files, which may be used to bypass security controls or deliver malicious payloads.

MITRE ATT&CK

T1566.001 T1204.002 T1486 T1027 T1573 T1036

defense-evasion

Detection Query

type.inbound
and any(filter(attachments, .file_type == "zip"),
        any(file.explode(.),
            .scan.zip.encrypted == true
            and any(.scan.zip.all_paths, strings.ends_with(., "vhdx"))
        )
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Raw Content

name: "Attachment: Encrypted ZIP containing VHDX file"
description: "Detects ZIP attachments that are encrypted and contain VHDX files, which may be used to bypass security controls or deliver malicious payloads."
type: "rule"
severity: "medium"
source: |
  type.inbound
  and any(filter(attachments, .file_type == "zip"),
          any(file.explode(.),
              .scan.zip.encrypted == true
              and any(.scan.zip.all_paths, strings.ends_with(., "vhdx"))
          )
  )
attack_types:
  - "Malware/Ransomware"
tactics_and_techniques:
  - "Encryption"
  - "Evasion"
detection_methods:
  - "Archive analysis"
  - "File analysis"
id: "bf477bfc-e1e4-5182-9ff8-9134c4378098"