Detection rules › Sublime MQL

Attachment: Finance themed PDF with observed phishing template

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

Detects PDF attachments containing a specific rectangular coordinate pattern at position [249.75 560 407.25 599.75], which may indicate a templated or malicious document structure.

Threat classification

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

CategoryValues
Attack typesCredential Phishing
Tactics and techniquesPDF, Evasion

Event coverage

Rule body MQL

type.inbound
and any(filter(attachments, .file_type == "pdf"),
        any(file.explode(.),
            any(.scan.strings.strings,
                strings.contains(., "/Rect [ 249.75 560 407.25 599.75 ]")
            )
        )
)

Detection logic

Scope: inbound message.

Detects PDF attachments containing a specific rectangular coordinate pattern at position [249.75 560 407.25 599.75], which may indicate a templated or malicious document structure.

  1. inbound message
  2. any of filter(attachments) where:
    • any of file.explode(.) where:
      • any of .scan.strings.strings where:
        • . contains '/Rect [ 249.75 560 407.25 599.75 ]'

Inspects: attachments[].file_type, type.inbound. Sensors: file.explode, strings.contains.

Indicators matched (2)

FieldMatchValue
attachments[].file_typeequalspdf
strings.containssubstring/Rect [ 249.75 560 407.25 599.75 ]