You may be a bit surprised to know that recovering deleted files from USB flash drives isn’t as difficult as you think. If you feel that on formatting the USB drive recovering a file is not possible, then give it a second thought. It is because, according to experts at How to Geek, the data recovery of internal SSDs is almost impossible due to the way the TRIM command works in them. While in the case of the external drives and flash drives, the TRIM working is not the same and the vulnerability to file recovery increases in these.
You must be using the formatting technique to the flash drive to prevent the recovery of deleted files, but formatting will only help if the Quick Formatting option is deselected before you format the drive.