syncAnnotScan annotation-staging primitive

syncAnnotScan() is a legitimate no-argument Acrobat / Foxit JavaScript API that ensures all annotation objects are populated before getAnnots() is called. It is not a vulnerable sink and has no associated CVE. However, exploit-kit JavaScript routinely calls it as a staging step in the pattern 'z.syncAnnotScan(); var p = y.getAnnots({nPage:0}); var s = p[0].subject; ... eval(s)' — where the encoded payload was hidden in annotation /Subject fields. A bare call rarely appears in legitimate PDFs, so it is a low-severity exploit-kit-shape indicator on its own; combined with getAnnots() + subject reads + eval, the related rule PDF_JS_OBFUSCATED_DROPPER fires the high-severity composite finding.