Tactic or Technique: QR code

QR codes are those square barcodes you scan with your phone to open a link. You’ve probably used them at restaurants, parking meters, or on event flyers. Attackers take advantage of how common and trusted they’ve become by hiding malicious links inside them. When scanned, a QR code can send you to a phishing site or install malware on your device.

These codes often appear in emails, attachments, or printed materials and are designed to look harmless. Some use redirect chains that pass through a URL shortener or compromised site before landing on the actual payload, making them harder to detect.

Because you can’t see where a QR code leads before scanning, and many scans happen on personal phones without enterprise protections, attackers get a reliable way to steal credentials, install malware, or access corporate systems through unmanaged devices.