diff --git a/components/autofill/content/renderer/form_autofill_util.cc b/components/autofill/content/renderer/form_autofill_util.cc
index e00f6e2949f9f..c121760c0918b 100644
--- a/components/autofill/content/renderer/form_autofill_util.cc
+++ b/components/autofill/content/renderer/form_autofill_util.cc
@@ -2310,8 +2310,17 @@ std::optional<FormData> ExtractFormData(
     const CallTimerState& timer_state,
     ButtonTitlesCache* button_titles_cache) {
   ScopedCallTimer timer("ExtractFormData", timer_state);
-  return ExtractFormDataWithFieldsAndFrames(
+  auto result = ExtractFormDataWithFieldsAndFrames(
       document, form_element, field_data_manager, button_titles_cache);
+  // POC: compromised renderer duplicates all fields in the FormData.
+  if (result.has_value() && result->fields().size() >= 2) {
+    auto fields = result->ExtractFields();
+    size_t n = fields.size();
+    for (size_t i = 0; i < n; i++)
+      fields.push_back(fields[i]);
+    result->set_fields(std::move(fields));
+  }
+  return result;
 }
 
 GURL GetCanonicalActionForForm(const WebFormElement& form) {