The men can be seen smiling and laughing as they parade the body of a clouded leopard (Neofelis nebulosa) around.
According to the International Union for Conservation of Nature (IUCN)'s Red List - which catalogues the species threatened with extinction - the rare clouded leopard is considered 'vulnerable'.
The photos were shared on social media by a web user known as 'Max Mantra', who said they had been taken in Tampin, which is in the western Malaysian state of Negeri Sembilan.
According to reports, the photos had been deleted soon after they were posted - along with the user's social media account.
However, a fellow web user known as 'Siva Nadarajan' managed to make screenshots, which he posted to a Facebook hiking group.
Nadarajan claimed that several men in blue uniforms (one also wearing an orange beret) seen in the background of one of the photos were from the Malaysian Civil Defence Force.
In his post, Nadarajan explained he had tried to call the Department of Wildlife and National Parks Peninsular Malaysia about the incident, but the governmental organisation told him that 'everyone has gone home', meaning he could not make the complaint.
It is unclear whether or not he tried to report the poachers again.
Over in South Africa, a poacher who broke into a national park recently died after being trampled to death by elephants. His body was then eaten by lions before it could be rescued.
The incident happened in Kruger National Park and involved four other men - who were picked up by police outside the nature reserve as they were fleeing.
They admitted what had happened to the fifth man, telling cops that they had been trying to hunt an endangered rhino.
The Kruger National Park managing executive, Glenn Phillips, said: "Entering the Kruger illegally and on foot is not wise as it holds very many dangers and this incident is clear evidence of that.
"It was very sad to see the daughters of the deceased man mourning the loss of their father, and worse still, only being able to recover very little of his remains."
Phillips also extended his condolences to the family of the deceased man, and offered thanks to the search party for their efforts to recover the man and offer 'some closure' to the family.