Imperva analyzed data collected from its customers between April 2015 and March 2016. The data showed a 211% increase year over year in the number of DDoS attacks directed against its customers. At least some of the growth had to do with the increased use of hit-and-run tactics by threat actors, Imperva says. The goal in using the tactic appears to be to exhaust mitigation teams by keeping them on high alert status for prolonged periods of time. About 16% of the DDoS victims that Imperva counted last year in fact were attacked more than one time.”]
Source: https://www.darkreading.com/attacks-breaches/hit-and-run-tactics-fuel-growth-in-ddos-attacks