The U.S. Department of State's Rewards for Justice (RFJ) program is offering up to $10 million for information on Zhang Yu, a Chinese national accused of hacking COVID-19 research at U.S. universities on behalf of China's Ministry of State Security (MSS). U.S. officials also describe Zhang as a key figure in the HAFNIUM hacking campaign, which compromised thousands of computers worldwide.

His alleged partner, Xu Zewei, was arrested in Italy in July 2025 and extradited to the United States in April 2026. Zhang remains at large.

Who Is Zhang Yu

Zhang is a director at Shanghai Firetech Information Science and Technology Company, Ltd. U.S. officials say he worked at the direction of the MSS Shanghai State Security Bureau (SSSB). According to RFJ, the MSS and SSSB are Chinese intelligence services responsible for domestic counterintelligence, non-military foreign intelligence, and parts of the country's political and domestic security.

[caption id="attachment_114641" align="aligncenter" width="600"] Image Source: Rewards for Justice[/caption]

The reward covers information leading to the identification or location of anyone who, while acting under the direction or control of a foreign government, takes part in malicious cyber activity against U.S. critical infrastructure in violation of the Computer Fraud and Abuse Act. The State Department says Zhang's cyberattacks violated that law.

Zhang Yu and the COVID-19 Research Intrusions

Starting in early 2020, Zhang and Xu allegedly gained unauthorized access to COVID-19 research conducted by U.S.-based universities and leading immunologists and virologists in order to steal sensitive information. At the time, Xu was a general manager at Shanghai Powerock Network Co. Ltd.

Prosecutors say the two men carried out the hacks at the behest of the MSS and SSSB and reported back to supervising officers at the SSSB. In one instance, Xu allegedly confirmed to his handlers that he had compromised the network of a research university in the Southern District of Texas.

The HAFNIUM Campaign Linked to Zhang Yu

In 2021, Zhang and Xu allegedly exploited vulnerabilities in computers running Microsoft Exchange Server, software used to store and retrieve emails. These intrusions were part of the mass hacking campaign publicly known as HAFNIUM. Victims included a university and a law firm, both based in the United States.

A nine-count indictment unveiled by the Justice Department in 2025 accused both men of computer intrusions between February 2020 and June 2021, including the HAFNIUM campaign, which prosecutors described as indiscriminate.

The scale of the campaign was significant. Brett Leatherman, assistant director of the FBI's Cyber Division, said in 2025 that through HAFNIUM, the Chinese Communist Party targeted more than 60,000 U.S. entities and successfully victimized more than 12,700 of them to steal sensitive information.

Zhang Yu Remains at Large as Partner Faces U.S. Charges

Xu was arrested by Italian authorities in July 2025 while on vacation in Milan. He was extradited to the United States in April 2026, while Zhang has not been apprehended.

According to RFJ, China uses an extensive network of private companies and contractors to hack and steal information in a way that hides the government's involvement. Both men worked for private Shanghai firms while allegedly acting on behalf of state intelligence services.

RFJ is asking anyone with information on Zhang, his associates, or their malicious cyber activities to submit a tip through its Tor-based tip line. Rewards of up to $10 million are available for information that meets the program's criteria.

The Shinhan Bank cyberattack has exposed personal and financial information belonging to about 25,000 customers in South Korea, with investigators examining whether advanced artificial intelligence tools were used to carry out the intrusion. The leaked information reportedly includes customers’ names, phone numbers, loan borrowing details and annual income. South Korea’s Financial Supervisory Service has launched an emergency on-site inspection as authorities investigate how the breach occurred and whether the suspected use of AI points to a wider risk for financial institutions.

Shinhan Bank Cyberattack Under Investigation

Shinhan Bank said the information was leaked on Wednesday after hackers gained access to its systems. The bank immediately formed a response team and took measures aimed at limiting further damage. These measures included blocking access from external IP addresses and suspending the affected services. The bank said it had completed safety measures related to the incident. Sources cited in the reports said the attackers are suspected to be based overseas and may have used advanced AI tools during the attack. Experts said the bank may not have been specifically targeted, but could instead have been caught in attacks against vulnerable online platforms. The Financial Supervisory Service sent a team to the bank to examine the incident. Its investigation is expected to take months as officials determine the nature and extent of the data exposure.

AI Agent-Assisted Attacks Raise Concern

The suspected use of AI has added another concern to the Shinhan Bank breach. Cybersecurity experts said AI tools originally developed or shared for defensive purposes can also be adapted for malicious activity. Mun Chong-hyun, director at cybersecurity firm Genians, said several recent attacks in South Korea have involved such AI tools. He described the technology as a double-edged sword because capabilities created for cybersecurity can also be used to facilitate cybercrime. The concern is not limited to Shinhan Bank. An industry official said the wider financial sector could be exposed to AI agent-assisted attacks, and that financial institutions should conduct their own security checks to identify potential weaknesses and abnormal access attempts. The incident also highlights the type of information that can be exposed in attacks against banks. Unlike a breach involving only basic contact information, the Shinhan incident reportedly exposed both personal details and financial information.

South Korean Banks Face More Data Breaches

The Shinhan Bank cyberattack comes amid several recent incidents affecting South Korean lenders. KB Kookmin Bank said last Friday that personal information belonging to 119 customers had been leaked following an external intrusion. Hana Bank also reported a separate hack affecting 89 customers. South Korea’s Financial Services Commission has already held a meeting with local banks over the recent breaches and is expected to hold another meeting this week. The latest incidents have raised concerns about how AI-powered hacking could affect the financial sector, particularly if attackers can use automated tools to identify vulnerable systems or support attacks at greater scale. The Shinhan incident is relatively small compared with some of South Korea’s largest data breaches in terms of the number of affected people. However, the combination of personal and financial information makes the breach significant. Sungho Hwang, Korea country manager at NordVPN, said the exposed information could be used to create personalized scams. He also noted that generative AI has made such scams more convincing.

South Korea Faces Wider Cybersecurity Pressure

The banking incidents come as South Korea cyberattacks have increased across other sectors. Cyberattacks targeting South Korean military systems reached 18,951 cases in 2025, the highest annual figure in five years. The number was up 31 percent from 2024 and 108 percent from 2022. South Korea has also expanded its use of AI for defensive cybersecurity. The Ministry of Education and the Korea Education and Research Information Service operate an AI-based system designed to detect suspicious activity and issue automated alerts across 435 monitored institutions. In 2025, the system detected about 480 million potential cyber threat indicators, of which around 86,000 were confirmed as actual intrusions. As the investigation into the Shinhan Bank breach continues, the suspected role of AI is adding to concerns that financial institutions may need to account for increasingly automated forms of cyberattacks.