I am not sure how extensive Crowdstrike's relationship was with the DNC. They came in to review how Bernie's people got access to one of Hillary's databases and then again for the DNC hack. There was a second IT firm with offices in Chicago and Washington that also worked for the DNC. I think they managed some aspect of their IT infrastructure..
Donna throws IT firm under the bus..
http://dailycaller.com/2017/11/07/donna-slams-obamas-chicago-tech-security-firm-over-russia-hacks/