China-linked hackers breached email systems used by US congressional staff, report says

China-linked hackers have allegedly compromised email systems used by congressional staff serving some of the most powerful committees in the US House of Representatives, in what has been described as part of a long-running cyber espionage operation known as Salt Typhoon, according to a report by the Financial Times.

The newspaper, citing people familiar with the matter, said the breaches form part of a broader campaign targeting sensitive political and government communications across the United States. Livemint could not independently verify the claims.

Powerful committees said to be affected

According to the FT report, Chinese intelligence accessed email systems used by staffers supporting key House committees, including those focused on China policy, foreign affairs, intelligence and armed services. The intrusions were reportedly detected in December, though it remains unclear whether the hackers gained access to lawmakers’ own email accounts.

People familiar with the incident told the Financial Times that the operation was linked to China’s Ministry of State Security, which is said to have been running Salt Typhoon for several years. The campaign allegedly enables access to unencrypted phone calls, text messages, voicemails and, in some cases, email accounts.

Long-running cyber campaign raises alarm

Salt Typhoon has previously been blamed for intercepting communications involving senior US officials over the past two years, according to people familiar with the operation. In December, Mark Warner, the top Democrat on the Senate intelligence committee, warned of the scale of the threat.

“Unless you’re on an encrypted device, they can pick any one of us,” Warner told the Defense Writers Group, calling it “baffling” that more attention was not being paid to the campaign.

Former national security adviser Jake Sullivan also told the Financial Times last year that US telecommunications companies were “highly vulnerable” to Salt Typhoon, highlighting long-standing weaknesses in digital infrastructure.

Wider pattern of cyber espionage

US authorities have repeatedly warned that Salt Typhoon is one of several Chinese cyber espionage efforts targeting American infrastructure. In 2024, the Federal Bureau of Investigation and other agencies said a separate Chinese state-sponsored hacking group, dubbed Volt Typhoon, had penetrated US energy, transport and communications networks in ways that could be exploited during a conflict.

Warner has argued that US networks remain especially exposed because they were built at a time when cyber security was not a core concern. Telecom companies, he said, have been slow to harden systems against such threats because of the high costs involved.

Diplomatic sensitivities and denials

The FT report said the US Treasury had planned to impose sanctions on Ministry of State Security-linked entities over Salt Typhoon in December, but reversed course amid concerns the move could undermine a fragile détente reached in October between Presidents Donald Trump and Xi Jinping.

The four congressional committees reportedly targeted declined to comment. The Chinese Embassy in the United States denied the allegations. Embassy spokesperson Liu Pengyu said: “We firmly oppose the US side making unfounded speculation and accusations, using cyber security to smear and slander China, and spreading all kinds of disinformation about the so-called Chinese hacking threats.”