That's it, when in doubt blame the Russians. They were being blamed for the WannaCry hack last Friday, now its N Korea. These are no more than conspiracy theories.
As far as 'hard Brexit' is concerned, the UK is a very big market for continental Europe, we too can slap tariffs on imports from the EU. BMW, VW, Peugeot, Renault, etc won't be too happy if a retaliatory import tax is levied upon their cars whilst Japanese, Chinese and other Asians enjoy more favourable terms. The same applies to French dairy produce, Spanish fruit and vegetables. It is in the EU's interest to hang on to its UK market.
I don't think we will lose our financial services either and no longer shackled by EU rules we can make ourselves very attractive to foreign investors.  The greatest gain will be taking back control over our borders and who we let in rather than being dictated to by unelected bureaucrats in Brussels: Parliament will once again be our supreme legislature.