No

A cyber attack is a cyber operation, whether offensive or defensive, that is reasonably expected to cause injury or death to persons or damage or destruction to objects.

Michael Schmitt et al; Tallinn Manual 1.0, pp 92
  • Cyber Operation?
  • Expected to cause death or injury to people or objects?
Chinese-linked Actors Probing The New York MTA's PulseSecure VPN does not match this definition. Here's a list of actual cyberattacks and and why this matters.

What happened?

A PulseConnect appliance belonging to the New York MTA was exploited at the beginning of 2021, possibly by a Chinese-backed actor, via a Pulse Secure VPN zero-day.

Transit systems systems weren’t accessed and it is believed no data was taken.