Well, what  impacted the outcome of the election was Wikileaks dumping embarrassing e-mails from the DNC, thereby influencing the voters. Obviously Wikileaks got the information from someone... but it wasn't the Russians.  
The FBI may be trying to find out who in fact did it. 
I'm pretty sure the Russian government cyber experts do hack into US business and political sites... but they didn't supply those DNC e-mails to Wikileaks. Think about it...  Julian Assange publicly stated his source wasn't Russian. He has no reason whatsoever to lie about that. Plus there are claims that the e-mails came from a disgruntled DNC insider.... way more likely.