Chinese Hackers Exploit Telecom Vulnerabilities in Sweeping Cyberattack

FBI and CISA Urge Americans to Switch to Encrypted Apps as Telecom Security Remains Uncertain

Amid an unprecedented cyberattack on major telecom providers like AT&T, Verizon, and Lumen Technologies, U.S. officials are urging Americans to start using encrypted messaging apps to keep their communications safe from prying eyes. The hacking campaign, named Salt Typhoon by Microsoft, is being called one of the largest intelligence breaches in U.S. history—and it’s far from resolved.

“This is a cyberespionage campaign,” a senior FBI official said during a press briefing on Tuesday. “The way they went about it was very specific to telcos and ISPs, but it fits into the cyberespionage bucket.”

A Deep Dive Into the Breach

Federal investigators shared that Salt Typhoon isn’t exploiting some new cutting-edge vulnerability — they’ve been leveraging existing weaknesses in telecom systems, particularly “Cisco-specific features” which are often used in communications networks. The attack, which reportedly began in late spring, has given Chinese hackers access to sensitive data such as phone call records, metadata, and even live calls from high-profile individuals in Washington, D.C.

Scott Putnam, chief information and security officer at New Charter Technologies, commented on the severity of such attacks:

“Unfortunately, Salt Typhoon is not an isolated incident; it fits within a broader pattern of advanced cyber campaigns linked to Chinese state-sponsored actors,” said Putnam. “From breaches targeting critical infrastructure to the theft of intellectual property, these activities have been on the rise, underscoring the need for increased vigilance across all sectors.”

It gets worse. The hackers also gained access to systems under the Communications Assistance for Law Enforcement Act (CALEA)—the infrastructure that allows court-ordered surveillance. While officials didn’t confirm if classified materials were compromised, privacy advocates like Senator Ron Wyden, D-Ore., were quick to point out the risks.

“When companies like AT&T, Verizon, Microsoft, and Google are inevitably hacked, adversaries can steal those communications,” Wyden said.

 Why Encryption Matters

During the press call, FBI and CISA officials strongly recommended using encrypted apps as a safeguard.

“Our suggestion, what we have told folks internally, is not new here: Encryption is your friend, whether it’s on text messaging or if you have the capacity to use encrypted voice communication,” Greene stated. “Even if the adversary is able to intercept the data, if it is encrypted, it will make it impossible.”

Putnam also emphasized the importance of encryption in protecting sensitive data.

“Protecting your communications doesn’t have to be complicated. Start by using encrypted messaging apps like Signal or WhatsApp and keeping sensitive information off unencrypted channels. These small steps can make a big difference in ensuring your personal data stays secure. With cybersecurity, a little prevention goes a long way.”

The FBI official went a step further, encouraging Americans to use phones that automatically update their operating systems, have strong encryption, and offer phishing-resistant multi-factor authentication.

No Clear End in Sight

Despite months of investigation, officials admit they’re still working to uncover the full extent of the breach. Further, they can’t fully rule out the possibility that Salt Typhoon hackers are simply lying low for now, ready to reactivate access once scrutiny eases.

“This threat actor has been in the telecom providers’ systems since at least May of 2024,” Putnam noted. “Anyone who has sent sensitive information, such as passwords, bank account details, or other private data, through unencrypted text messages may have already had that information compromised and should take immediate action. Start by changing any passwords you’ve shared and enable multi-factor authentication for added security.”

“It’s impossible to predict a timeframe for when we’ll achieve full eviction,” added Greene.

This lack of clarity is precisely why Americans are being urged to act now to protect themselves. Using apps like Signal or WhatsApp, which automatically encrypt messages and calls, is a simple step that can make a big difference. Google Messages and iMessage are also solid options for end-to-end encryption.

Balancing Security and Surveillance

Encryption has always been a hot topic for federal law enforcement. While agencies like the FBI have historically resisted full end-to-end encryption that blocks even court-ordered access, they’ve acknowledged its importance in cases like this.

Putnam concluded: “The trend of increasing cyber activity by nation-state actors like China is clear, and the risks are growing. As these campaigns evolve, so must our defenses. Whether it’s using encrypted communication tools, keeping software updated, or adopting a zero-trust security approach, everyone—from individuals to enterprises—has a role to play in building a more secure digital future.”

Even though ‘Salt Typhoon’ seems to be focused on spying and espionage rather than election interference, the breach serves as a stark reminder of how vulnerable telecom systems can be to state-sponsored attacks. As federal investigators work to close the gaps, the message for Americans is simple: Secure your communications now and stay alert.

The uptick in Chinese state-sponsored hacking calls for a collective focus on security. Whether it’s Salt Typhoon or the widespread exploitation of zero-day vulnerabilities earlier this year, these incidents remind us that proactive risk management and improved resilience are more important than ever.

Recent breaches have shown that no sector is immune. From the targeting of government emails to the compromise of telecom systems, these attacks highlight the importance of adopting zero-trust principles and ensuring that both organizations and individuals take steps to secure their digital environments.

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