Also received a call on on the voice mail, on the voice mail you hear a police siren in the background, feed back from an an electronic device, then a recording about an expiring security certificate on a website (which ours isn't expiring). Smells like a scam.
... after a long pause (~20 seconds) with unintelligible noise in the background. Hello, we're calling in regards to an expiring security certificate on one of your websites...
They ask to call back at 973-915-3190. It could be a telemarketer or scammer but it doesn't matter. I treat both the same, no call back.
This is from Comodo SSL who saw our company's SSL certificate purchased from another issuer (GoDaddy) was about to expire. They identified themselves only as "The Certificate Issuer" and were trying to get us to switch to their SSL Certificate instead of renewing through GoDaddy. They repeatedly call despite our telling them not to. I simply won't talk to them anymore. Don't waste your time.