Chinese national behind 911 S5 botnet arrested in Singapore

The US Department of Justice (DOJ) announced the arrest of a Chinese national, Wang Yunhe, in an international operation targeting cybercrime. Wang, aged 35, was apprehended in Singapore on 24 May for allegedly creating and using malware responsible for cyberattacks, large-scale fraud, and child exploitation. This arrest comes on the heels of a similar high-profile sweep last August, involving 10 Chinese citizens charged with laundering over $2 billion through Singapore.

According to the US Treasury Department, the botnet, known as ‘911 S5,’ was used by criminals to compromise personal devices to further conduct identity theft, financial fraud, and child exploitation.

The Treasury’s Office of Foreign Assets Control has now imposed sanctions on three Chinese nationals behind the platform—Yunhe Wang, Jingping Liu, and Yanni Zheng—and on three entities owned or controlled by Yunhe Wang. FBI Director Christopher Wray described the ‘911 S5’ botnet as likely the world’s largest, comprising malware-infected computers in nearly 200 countries.

According to the DOJ, Wang and unnamed accomplices developed and distributed malware that compromised millions of residential Windows computers worldwide. From 2018 to July 2022, Wang accrued $99 million from selling access to hijacked IP addresses, facilitating cybercriminals in bypassing financial fraud detection systems. These criminals committed fraud, resulting in losses exceeding $5.9 billion, including 560,000 fraudulent unemployment insurance claims.

Wang used the illicitly obtained proceeds to acquire assets globally, spanning properties in the USA, Saint Kitts and Nevis, China, Singapore, Thailand, and the UAE. His possessions included luxury sports cars, numerous bank accounts, cryptocurrency wallets, luxury watches, and 21 properties across multiple countries. Matthew S. Axelrod from the US Department of Commerce’s Bureau of Industry and Security described the case as resembling a screenplay, highlighting the extensive criminal enterprise and lavish expenditures financed by nearly $100 million in profits.

The operation is a collaborative effort led by law enforcement agencies from the US, Singapore, Thailand, and Germany. It underscores the international cooperation required to combat cybercrime effectively.

The FBI has published information at fbi.gov/911S5 to help identify and remove 911 S5’s VPN applications from infected devices.