Redback spider in the building

I took this photo along the hallway where we live.
Not sure if it was poisonous or not but it looks scary, huge and very much different from the spiders I used to play with when I was still in the Philippines. I took a photo of the spider then I spray insecticide in the hallway before it cause any harm.

I look at the internet of its description and found out that it is one of Australia's poisonous spider (The Redback spider).

Rereference: (http://en.wikipedia.org/wiki/Redback_spider)
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The Redback spider (Latrodectus hasselti) is a potentially dangerous spider native to Australia that resembles a Black widow spider. It is a member of the genus Latrodectus or the widow family of spiders, which are found throughout the world. The female is easily recognisable by its black body with prominent red stripe on its abdomen. Females have a body length of about a centimetre while the male is smaller, being only 3 to 4 millimetres long. The Redback spider is one of few animals which display sexual cannibalism while mating.

Redbacks are considered one of the most dangerous spiders in Australia.[1] The Redback spider has a neurotoxic venom which is toxic to humans with bites causing severe pain. There is an antivenom for Redback bites which is commercially available.
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