I received a tampered USB drive and performed a detailed analysis on it. 1. Why Does the USB Drive Appear to Have 2 TB? All of these tools read the information reported by the device firmware. They do NOT verify the physical storage capacity. They simply display what the USB controller claims. Command What it checks Expected result on a counterfeit USB drive lsblk -d -o NAME,SIZE,MODEL,VENDOR,TRAN Displays the reported size, model, vendor and transport type. SIZE = 1.9T sudo fdisk -l /dev/sda Reads the disk geometry reported by the firmware. Disk /dev/sda: 1.91 TiB sudo blockdev --getsize64 /dev/sda Returns the total size (in bytes) reported by the kernel. ≈ 2097152000000 bytes cat /sys/class/block/sda/size Shows the number of sectors reported by the device. Value corresponding to ~2 TB sudo hdparm -I /dev/sda (if supported) Displays ATA/USB device information. May report the advertised capacity sudo parted /dev/sda print Reads the disk geometry reported by the device. Disk ≈ 1.91 TiB Conclusion These tools are not wrong. They simply display the information provided by the device firmware. If the firmware has been modified to report a fake capacity, every one of these tools will display the fake size. 2. How to Verify the REAL Capacity These tools actually write and read data to verify that the storage physically exists. These tools verify the actual physical capacity of the device. ⚠ WARNING: Commands marked as destructive will erase all data on the USB drive. Command What it does Expected result sudo f3probe --destructive /dev/sda Writes test patterns across the device and measures its real capacity. (Destructive) Reports the actual usable capacity. f3write /mountpoint + f3read /mountpoint Fills the filesystem with test files, then verifies them. (Non-destructive to the partition layout, but requires free space.) Detects fake capacity and data corruption. h2testw (Windows) Writes and reads the entire device. Detects counterfeit flash drives. Fight Flash Fraud (F3) Complete Linux/macOS toolkit for testing flash media. Detects fake-capacity firmware.