A group of Chinese hackers infiltrated multiple US telecommunications firms in search for sensitive information on issues like national security, CNN reported citing multiple sources.The US investigators identified US broadband and internet providers AT & T, Verizon and Lumen among the targets of the recent slew of cyber-attacks launched against the US.Notably, as the backbone of internet and phone communications, US telecom firms hold enormous volumes of caller and user data.The Chinese Embassy in Washington, DC, denied that Beijing-backed hackers had breached US telecom firms, calling that information "a distortion of the fact." Embassy spokesperson Liu Pengyu accused the US of "politicizing cybersecurity issues to smear China", CNN noted.The matter has been taken up by the highest echelons of the US administration. US officials have briefed the House and Senate intelligence committees on the Chinese hacking campaign, two sources said. Cybersecurity experts from Microsoft and ...