Washington, DC, December 4: Chinese hackers have been accused of compromising US telecommunications systems and engaging in espionage on American presidential campaigns, with US officials warning that it may take years before the hackers are removed from the network, VOA News reported.

The US Cybersecurity and Infrastructure Security Agency (CISA) and the FBI on Tuesday called on US telecommunication companies and their customers to take more precautions, stressing the breach might go deeper than first thought.

Speaking at a briefing with reporters, Jeff Greene, CISA's executive assistant director for cybersecurity, said, "We cannot say with certainty that the adversary has been evicted because we still don't know the scope of what they're doing." Greene said, "We cannot with confidence say that we know everything, nor would our partners," adding that, "We're still trying to understand." Donald Trump Thanks Americans for Electing Him As 47th, 45th President While Delivering Victory Address in Florida, Says 'Will Fight for You With Every Breath in My Body' (Watch Video).

A senior FBI official also discussed breach investigation. The official, who spoke on the condition of anonymity said, "Understanding the scope of the adversary activity through our investigations, in a situation of this magnitude, is measured in years," according to VOA News report. The official further warned, "As more comes to light they change their TTPs [tactics, techniques and procedures] and their approach." The official said, "They may go dormant for a while to lower their profile."

The breach, first revealed in October, is attributed to Salt Typhoon, a Chinese-linked cyber gang suspected of targeting communications networks to spy on the presidential campaigns of both US President-elect Donald Trump and his Democratic challenger, Vice President Kamala Harris. The hackers have reportedly adapted their tactics as more details about their activities have surfaced, complicating the ongoing investigation. China Releases 3 Americans It Imprisoned for Years, Beijing Says US Returned 4 People to China.

According to the VOA, both CISA and the FBI emphasized the uncertainty surrounding the long-term impact of the breach. The FBI official warned that fully understanding the scope of the hackers' operations could take years due to the complexity and scale of the intrusion. China has repeatedly rejected the US allegations. With regards to the latest US allegations, Liu Pengyu, the spokesperson for the Chinese Embassy in Washington, in an email to VOA News said, "For quite some time, the US side has patched up all sorts of disinformation about threats of 'Chinese hackers' to serve its own geopolitical purposes."

Liu said China opposes and combats all kinds of cyber attacks and called on US to stop its cyberattacks against other nations. Liu said, "The US needs to stop its own cyberattacks against other countries and refrain from using cyber security to smear and slander China." Despite China's denial, US officials have said that the Chinese breach is more than initially thought, affected telecommunication firms around the world, and that it seems to be part of a larger Chinese government effort to collect information about adversaries around the world, according to VOA News report.

The senior FBI official said, "Certainly, the way they went about it was very, very specific," noting the focus on telecommunications infrastructure and internet service providers. The official said, "But it fits into the cyber espionage bucket to really inform global goals for the Chinese." The CISA and the FBI did not mention the number of telecommunication companies or countries who have been affected. According to the agencies, the Chinese efforts in the US fall into three categories: individual communications, call record of customers and US law enforcement requests pursuant to court orders.

(This is an unedited and auto-generated story from Syndicated News feed, LatestLY Staff may not have modified or edited the content body)