← All detection heuristics · Social engineering
high
PDF_NESTED_ENCODED_CROSSHOST_REDIRECT
What it means
A PDF link hides a different destination host behind multiple percent-encoding layers.
Why it fires
The rule requires a redirect parameter, at least two encoded layers, and a registrable host change; ordinary encoded query values do not match.
Other Social engineering heuristics
SE_BOOKING_COMPLAINT_PHISH PDF_FAKE_DOCUMENT_COMPONENT_INSTALLER OOXML_QR_CREDENTIAL_PHISH SE_CALLBACK_SCAM_TEMPLATE PDF_BRAND_ACCOUNT_UPDATE_REDIRECT_LURE PDF_IMAGE_REPEATED_DECOY_REDIRECT_LURE PDF_IMAGE_DOCUMENT_REVIEW_HOST_LURE PDF_LOCALIZED_DOWNLOAD_HOSTING_LURE PDF_MINIMAL_VIEW_DOCUMENT_REDIRECT PDF_RFP_EXTERNAL_ACTION_LURE PDF_UTILITY_REFUND_OFFDOMAIN_LURE PDF_SPARSE_MOVED_ARTICLE_DOORWAY