INSPIRON 14-3467 cursor moving randomly while i'm typing

I bought the INSPIRON 14-3467 (7th generation Intel Core Processor, i5-7200U, Ubuntu Linux 16.04 operating system, worldwide factory installation) not yet a year old.

Now, a month or two ago, this problem has started: the cursor moves by itself as I type, and I'm pretty sure I'm not touching the touchpad. I need support to solve this tremendous inconvenience - which is also a great frustration.