The group, OurMine, posted tweets promoting its own website and services.
However, the tweets were removed about an hour after the first one appeared.
OurMine has hacked several high-profile Twitter accounts this year, including those of Wikipedia co-founder Jimmy Wales, Facebook co-founder Mark Zuckerberg and Google chief executive Sundar Pichai.
It also hacked the Techcrunch and BuzzFeed websites, as well as the Twitter and Vine accounts of the social media platforms' chief executive Jack Dorsey.
"Don't worry we are just testing your security," read one of the tweets posted to the Netflix account.
The hackers told the BBC they still had access to the account, adding that they were still posting tweets, but these were being deleted "by Twitter Support".
The Netflix US Twitter account - with 2.5m followers - has been compromised by a hacker group.