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// MakeNotWork - VBA auto-exec macro droppers. |
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// Office documents that auto-run a macro which shells out or pulls a payload. |
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// The auto-exec entrypoint alone is common in benign templates, so it must |
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// co-occur with an execution/download primitive to fire. Untrusted uploads are |
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// held regardless; this flags the obvious macro-dropper shape in-process. |
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|
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rule office_macro_autoexec_dropper { |
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meta: |
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description = "VBA auto-exec macro paired with shell/download primitives" |
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strings: |
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$auto1 = "AutoOpen" ascii nocase |
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$auto2 = "Document_Open" ascii nocase |
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$auto3 = "Auto_Open" ascii nocase |
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$auto4 = "Workbook_Open" ascii nocase |
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$exec1 = "WScript.Shell" ascii nocase |
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$exec2 = "Shell(" ascii nocase |
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$exec3 = "CreateObject" ascii nocase |
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$exec4 = "URLDownloadToFile" ascii nocase |
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$exec5 = "MSXML2.XMLHTTP" ascii nocase |
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condition: |
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(1 of ($auto*)) and (2 of ($exec*)) |
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} |
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