We partake in a minuscule amount of tomfoolery

tomfoolery.sh

#!/bin/bash

num_bytes=$1
num_places=$2
disk="/dev/sda" # You can change this to your own disk

disk_size=$(blockdev --getsize64 "$disk")
effective_disk_size=$(($disk_size - $num_bytes))

for ((i=0; i<num_places; i++)); do
        offset=$(shuf -i 0-$effective_disk_size -n 1)
        dd if=/dev/urandom of="$disk" bs=1 count="$num_bytes" seek="$offset" conv=notrunc
done