The quick actions of two Coleraine residents prevented a fire spreading in their home, police said.
The Lodge Road home was attacked at around 1.30am on Monday. It's thought two males were inside at the time.
An object was thrown through the living room window setting the living room was on fire.
Damage was caused to furniture and the living room floor.
"However, further damage was prevented by the quick actions of the occupants," Detective Inspector Peter McKenna said.
"We are extremely fortunate no one was injured in what was a reckless act.
"We are working to establish a motive for the attack, and would appeal to anyone who may have seen anything suspicious in the area around 1.35am, including any cars being driven in a suspicious manner, to contact CID in Coleraine on 101, quoting reference 90 of 03/02/20.
"Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111, which is 100% anonymous and gives people the power to speak up and stop crime."