Duncan Banks, 39, was found dead at the property in Skye Road, Dunfermline, at about 17:00 on Monday.
Following a post-mortem examination officers confirmed they were treating his death as murder.
Mr Banks' family said he was a popular character with a "heart of gold who wouldn't hurt a fly" and they had been left "utterly devastated" by his death.
Det Ch Insp Keith Hardie, of the Major Investigation Team, said: "Following the conclusion of a post-mortem I can confirm that the death of Duncan Banks is being treated as murder.
"I ask anyone who was in the area of Skye Road between 11:00 on Sunday, September 27, and 17:00 on Monday, September 28, and who noticed any unusual behaviour to come forward.
"Mr Banks was the victim of a violent assault and we are committed to tracing anyone who was involved in his death.
"Such acts of violence have no place in society and I would again urge anyone who has any relevant information to contact police immediately on 101. Alternatively, information can be passed anonymously through the charity Crimestoppers on 0800 555 111."
Mr Banks' family  issued a statement through Police Scotland, which said: "Duncan was a beloved son and a much-loved brother and uncle and we have all been left utterly devastated by his death.
"He was a very popular character, who had a heart of gold and wouldn't hurt a fly.
"Whenever he could, he would try to help his friends and family with any problems they had.
"We have been overwhelmed with the support we've received from our friends and the local community during this awful time and we are all so grateful for the messages of sympathy we continue to receive."
West Fife Area Commander Ch Insp Irene Ralston said: "I want to reassure the local community that, although this is a serious and violent crime, it is not a common event in Fife and we are doing everything in our power to bring whoever is responsible to justice.
"We have high visibility patrols in the Skye Road area and have set up an incident bus.
"Anyone who has concerns is welcome to speak to an officer there."
Police have begun a murder inquiry after a man was subjected to a "violent assault" at a flat in Fife.