This article originally appeared on ABACUS Nearly 350 people from a cross-border prostitution ring have been arrested in Malaysia and China -- accused of using WeChat to conduct their illicit operation. The ring-leaders allegedly set up a tech company in southern China to mask their criminal activities, according to local media. They created a mini program within WeChat to run brothels in Malaysia -- and conducted cash transactions through the multi-purpose app. Many of the prostitutes were sent to Malaysia from China. Authorities said the suspects tried to trick potential customers into believing the women were models and actresses by creating fake websites. Transaction records showed the ring earned around US$15.8 million last year. The arrest was the result of a three-month investigation and coordination between police in China and Malaysia. Malaysia received an upgrade in the 2017 US State Department Trafficking in Persons report for making increasing efforts to expand investigations and prosecutions, although efforts to protect victims were still considered inadequate. The country said in January it was setting up a special court to process human trafficking cases. For more insights into China tech, sign up for our tech newsletters , subscribe to our Inside China Tech podcast , and download the comprehensive 2019 China Internet Report . Also roam China Tech City , an award-winning interactive digital map at our sister site Abacus .