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?
The Ghostwriter Influence Operation in Poland does not match this definition. Here's a list of actual cyberattacks and and why this matters.

What happened?

A hacking group compromised the social media accounts of Polish officials and used them to disseminate narratives critical of NATO. German authorities have reported that the same group has also attempted to compromise members of the Bundestag and state parliament.