Be vigilant - Voice phishing scams are becoming harder to differentiate. However, old school best practices still help. Never, give out your PIN or any security information over the Phone

Fraudsters can use a variety of open-source and free tools to fake or “spoof” the number displayed as the caller ID, lending legitimacy to phone phishing schemes. Often, just sprinkling in a little foreknowledge of the target’s personal details — SSNs, dates of birth, addresses and other information that can be purchased for a nominal fee from any one of several underground sites that sell such data — adds enough detail to the call to make it seem legitimate.

https://krebsonsecurity.com/2018/10/voice-phishing-scams-are-getting-more-clever/