Defendr checks images, the QR codes inside them and file attachments. Images are matched against reviewed scam images by a perceptual hash, so a recoloured or cropped copy still matches. QR codes are read and their link is checked like any other link. Attachments are checked by name and by their first bytes. Nothing is uploaded anywhere and no image is ever copied into a log channel.
Example
/setup › Settings › Browse all settings › Media & files