diff --git a/detection-rules/attachment_targeted_docx_ack_lure.yml b/detection-rules/attachment_targeted_docx_ack_lure.yml new file mode 100644 index 00000000000..f39c26b6011 --- /dev/null +++ b/detection-rules/attachment_targeted_docx_ack_lure.yml @@ -0,0 +1,41 @@ +name: "Attachment: Targeted DOCX with personalized recipient acknowledgement lure" +description: "Detects inbound messages with a DOCX attachment containing a quarterly date reference, specific STATUS and ACKNOWLEDGEMENT formatting patterns, and a personalized salutation where the recipient's name or local email part is dynamically embedded in the document XML." +type: "rule" +severity: "medium" +source: | + type.inbound + and any(filter(attachments, .file_type == "docx"), + any(filter(file.explode(.), .file_name == "word/document.xml"), + // doc xml has a QX 2026 type date + regex.contains(.scan.strings.raw, 'Q[1-4]\S202[5-9]<\/w:t>') + // and a couple of the terms we've seen in the document with specific spacing reqs + and strings.contains(.scan.strings.raw, + 'STATUS ' + ) + and strings.contains(.scan.strings.raw, + 'ACKNOWLEDGEMENT ' + ) + // and doc xml has some reference to the user's name in there too? + and any(regex.extract(.scan.strings.raw, + 'Dear (?P.*?)' + ), + any(recipients.to, + ( + ..named_groups["name"] =~ .email.local_part + or ..named_groups["name"] =~ .display_name + ) + ) + ) + ) + ) + +attack_types: + - "Credential Phishing" +tactics_and_techniques: + - "Social engineering" +detection_methods: + - "Archive analysis" + - "Content analysis" + - "File analysis" + - "XML analysis" +id: "095c280f-0a50-528f-84aa-35262a4ce768"