Which tool can be used to silently copy files from USB devices?

USB Grabber is a hardware or software term typically associated with capturing video/audio signals from USB capture cards, not silently copying file contents.

USB Dumper runs in the background and monitors for USB storage devices; when one is detected, it copies all contents to a preconfigured local folder without displaying any dialog or notification to the user. This makes it effective for covert data exfiltration from shared or unattended machines and is a well-known tool covered in ethical hacking courses such as CEH.

USB Sniffer tools capture and analyze USB protocol traffic at the bus level for debugging purposes - they do not copy stored files from the device's filesystem.

USB Snoopy is not the recognized tool for this specific covert file-copying function and is not a standard utility in this category.