Amazon's chief security officer is taking measures to defend the company against infiltration attempts by North Korean IT workers. There are reports of fake North Korean IT workers on LinkedIn, with security experts warning that they are stealing profiles to apply for jobs and infiltrate firms, although the number of such attempts at Amazon is unclear, with one report suggesting 1,800 suspected applications were blocked. Meanwhile, a separate cyber threat, reportedly from Russia and lasting five years, has also been confirmed by Amazon.