In most cases, however, drawing boxes over text in a PDF just adds the boxes—it doesn’t delete the text underneath them. Someone who would like to extract the text beneath the obfuscation can ...

such as adding new text boxes that overlay the original text in the PDF, using the pen tool to draw over the text with your chosen color, or highlighting the text by applying a translucent color ...

Step 6: If you select the inserted text box, you’ll see a floating toolbar display beneath it. You can use this to wrap other text around it or keep it inline, as well as rotate or resize the box.