U.S. Government Disrupts Botnet People’s Republic of China Used to Conceal Hacking of Critical Infrastructure

The hackers, known to the private sector as “Volt Typhoon,” used privately-owned SOHO routers infected with the “KV Botnet” malware to conceal the PRC origin of further hacking activities directed against U.S. and other foreign victims. These further hacking activities included a campaign targeting critical infrastructure organizations in the United States and elsewhere that was the subject of a May 2023 FBI, National Security Agency, Cybersecurity and Infrastructure Security Agency (CISA), and foreign partner advisory. The same activity has been the subject of private sector partner advisories in May and December 2023, as well as an additional secure by design alert recently released by CISA.

The vast majority of routers that comprised the KV Botnet were Cisco and NetGear routers that were vulnerable because they had reached “end of life” status; that is, they were no longer supported through their manufacturer’s security patches or other software updates. The court-authorized operation deleted the KV Botnet malware from the routers and took additional steps to sever their connection to the botnet, such as blocking communications with other devices used to control the botnet.

As described in court documents, the government extensively tested the operation on the relevant Cisco and NetGear routers. The operation did not impact the legitimate functions of, or collect content information from, hacked routers. Additionally, the court-authorized steps to disconnect the routers from the KV Botnet and prevent reinfection are temporary in nature. A router’s owner can reverse these mitigation steps by restarting the router. However, a restart that is not accompanied by mitigation steps similar to those the court order authorized will make the router vulnerable to reinfection.

The FBI is providing notice of the court-authorized operation to all owners or operators of SOHO routers that were infected with the KV Botnet malware and remotely accessed pursuant to the operation. For those victims whose contact information was not publicly available, the FBI has contacted providers (such as a victim’s internet service provider) and has asked those providers to provide notice to the victims.

FBI Houston Field Office and Cyber Division, U.S. Attorney’s Office for the Southern District of Texas, and National Security Cyber Section of the Justice Department’s National Security Division led the disruption effort. The Justice Department’s Criminal Division’s Computer Crime and Intellectual Property Section and Office of International Affairs provided valuable assistance. These efforts would not have been successful without the partnership of numerous private-sector entities.

If you believe you have a compromised router, please visit the FBI’s Internet Crime Complaint Center or report online to CISA. The remediated routers remain vulnerable to future exploitation by Volt Typhoon and other hackers, and the FBI strongly encourages router owners to remove and replace any end-of-life SOHO router currently in their networks.

The FBI continues to investigate Volt Typhoon’s computer intrusion activity.