Beware of threats lurking in booby-trapped PDF files

This article warns that PDFs are frequently abused in phishing and broader cybercrime operations, describing techniques such as embedded JavaScript, malicious links, exploiting vulnerable PDF readers, and files masquerading as PDFs; it cites telemetry indicating PDFs rank among top malicious attachment types and references a Grandoreiro banking‑trojan lure as an example. It offers practical red flags and defenses—verifying senders and context, checking file extensions, scanning with security tools, opening in Protected View/sandboxed readers—and provides response steps if a suspicious PDF is opened, alongside general hygiene like patching and adjusting PDF JavaScript settings.