Every seven minutes a cyber-attack is reported in Australia.
Millions of Australians have had their data stolen in malicious attacks, costing some businesses tens of millions of dollars in ransom.
The federal government is warning the country must brace for even more strikes as cyber gangs become more sophisticated and ruthless.
Four Corners investigates the cyber gangs behind these assaults, cracking open their inner operations and speaking to a hacker who says he targets Australians and shows no remorse.
The program travels all the way to Ukraine and discovers we share a common enemy in the battle for cyber security.