Can I scan to a PDF file?
No, the printer doesn't allow you to scan to PDF. According to the official specifications, the printer supports the following scanning methods: PC, email, USB. For more information, I recommend visiting the official website of the manufacturer.
There is an application called Vuescan which has support for PDF scanning. I recommend checking the official website to find out more. Download the software, install it, then make sure your device is ready for scanning and attached to PC. Press Scan and select the output as PDF and that's it.
VueScan's homepage: http://www.hamrick.com/vuescan/samsung_scx_5x3x.html
Drivers for device: http://www.samsung.com/us/support/owners/product/SCX-4826FN/XAA