Detection rules › Sublime MQL

Link: SVG with embedded recipient data

Severity
high
Type
rule
Source
github.com/sublime-security/sublime-rules

Detects SVG links that contain the recipient's email address either in plain text or base64 encoded format within the URL, indicating potential tracking or targeting mechanisms.

Threat classification

Sublime's own taxonomy (not MITRE ATT&CK).

CategoryValues
Attack typesCredential Phishing
Tactics and techniquesEvasion

Event coverage

Rule body MQL

type.inbound
and any(body.links,
        strings.iends_with(.href_url.path, '.svg')
        and any(recipients.to,
                .email.domain.valid
                // contained in the url
                and (
                  strings.icontains(..href_url.url, .email.email)
                  // or contains the base64 endcoded email
                  or any(strings.scan_base64(..href_url.url,
                                             format="url",
                                             ignore_padding=true
                         ),
                         strings.icontains(., ..email.email)
                  )
                )
        )
)

Detection logic

Scope: inbound message.

Detects SVG links that contain the recipient's email address either in plain text or base64 encoded format within the URL, indicating potential tracking or targeting mechanisms.

  1. inbound message
  2. any of body.links where all hold:
    • .href_url.path ends with '.svg'
    • any of recipients.to where all hold:
      • .email.domain.valid
      • any of:
        • strings.icontains(.href_url.url)
        • any of strings.scan_base64(.href_url.url) where:
          • strings.icontains(.)

Inspects: body.links, body.links[].href_url.path, body.links[].href_url.url, recipients.to, recipients.to[].email.domain.valid, recipients.to[].email.email, type.inbound. Sensors: strings.icontains, strings.iends_with, strings.scan_base64.

Indicators matched (1)

FieldMatchValue
strings.iends_withsuffix.svg