Must be spam?

got a call from this number no person on the other end

Received a call from 617-778-2338 answered and no one was there, called backed repeatedly and got a busy signal,  617 area code shows up as located in Ma.

Received a call from 617-778-2338 and let it go to voicemail. They did leave a message but it was as if they had started talking before the beep, so all I heard was something about "searching for qualified job applicants with disabilities" and I deleted the message after that and blocked the number.

This is the second time i have recieved a call from this number. They left a message this time about finding jobs for people with disabilities. Message is going to get deleted and number will be blocked from now on.