sublimehighRule

Link: URL fragment with hexadecimal pattern obfuscation

Detects links containing URL fragments with repeating hexadecimal patterns, commonly used to obfuscate malicious destinations or bypass security filters.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598 T1036 T1027

defense-evasion

Detection Query

type.inbound
and any(body.links,
        regex.contains(.href_url.fragment, '.html\/\?(?:[a-f0-9]{2}\.){12,}')
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Raw Content

name: "Link: URL fragment with hexadecimal pattern obfuscation"
description: "Detects links containing URL fragments with repeating hexadecimal patterns, commonly used to obfuscate malicious destinations or bypass security filters."
type: "rule"
severity: "high"
source: |
  type.inbound
  and any(body.links,
          regex.contains(.href_url.fragment, '.html\/\?(?:[a-f0-9]{2}\.){12,}')
  )
attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "Evasion"
detection_methods:
  - "Content analysis"
  - "URL analysis"
id: "51f51aa0-4e62-5140-8baa-014cd95f7a46"