Telephonic DoS attacks have been around for a while, but don’t get as much attention as DDoS attacks. The late December attack against a Ukrainian power company was a smokescreen to cover up a cyber attack, experts say. Successful cyber attacks against critical infrastructure have been steadily increasing in frequency and complexity over the past decade, according to a recent Trend Micro report. Businesses can protect themselves with countermeasures such as protection gateways and firewalls that validate incoming calls.”]