Is this a deliberate attempt to mess with our traffic?

Hi there! Desperate for some help! We have an ecommerce website which ranks very well on Google - lots of important terms for our industry in positions 1-3. Since last friday, we've began to notice an influx of organic traffic from our own country and areas that we mostly serve to some of our Top Ranking web pages (also the pages that most of our competitors would like to destroy). The referrer is google.com (even thought we're a Canadian site .ca) and most visits are only 10 seconds long with no further actions. So whereas at first it seemed that our traffic was increasing, we quickly noticed that it is low quality and problematic as it bring up our bounce rate. Our good quality hits to those pages are going down, too. Traffic also comes from many different local IPs - so it is hard to track. We've been working on SEO for a while and know about click farms that usually target paid ads. But targeting organic results this way - is it a thing? And is there anything we can do to get rid of the problem? Would really appreciate your thoughts!