Three people died at the house, in the city of Orinda, near San Francisco, and two more died later in hospital, BBC reports.
The house was reportedly booked under a pretence for a small group, before being publicised on Instagram as the venue for a Halloween party which eventually drew a crowd of more than 100 people. The host did not authorise the party, Airbnb said.
In response to the shooting, which left several others injured, Airbnb CEO Brian Chesky announced on Twitter that the company was banning "party houses" from the short-term rental platform.
As part of that effort, the company will do more manual screening of reservations marked as high-risk by the company's "risk detection technology."
On Friday (local time), Airbnb spokesman Ben Breit said the risk-scoring system was intended to "help prevent bad actors from ever accessing our platform in the first place."
The company uses technology such as machine learning to analyze hundreds of possible red flags.
"When we detect potentially concerning behavior, our team takes a range of actions, including removing a user from the platform entirely," Breit said.
The company will also create a rapid response team for party houses and take "immediate action," including removal, against users that violate what Chesky called "enhanced guest policies."
The changes will be led by Margaret Richardson, vice president for trust at Airbnb, whose team will "initiate a 10 day sprint" to develop and speed up the implementation of the changes, Chesky tweeted.
"We must do better, and we will," he tweeted. "This is unacceptable."
