The FBI just released another private industry notification to warn enterprises about contined Telephony Denial of Service (TDoS) attacks. The FBI warns that the attacks tend to target hospitals and Public Safety Access Points (PSAPs), the administrative part of a 911 center. Here is a PDF - I don't have a link:
The FBI predicts that TDoS will become the go-to attack against any enterprise who is heavily depending upon their voice systems. This includes any enterprise, but in particular, those with public facing contact centers, in the financial, health care, government, retail, and safety sectors.
The notifications states that since 2013, there have been 1000 REPORTED attacks - there have certainly been more that were not detected.
The notification also provides recommendations for mitgiation of the issue. SecureLogix has cloud and premise based solutions that address this issue. Most enterprises experiencing these attacks can point their voice systems to our cloud based solutions and begin solving the issue almost immediately.