Cryptjacking is fast becoming a popular way for cyber crooks to make money. For instance, around 5% of the cryptocurrency Monero currently in circulation is estimated to have been mined fraudulently, according to security firm Palo Alto Networks. Over the weekend it was reported that a ring of cyber criminals in China had conspired with computer maintenance companies in the country to inject computers belonging to internet cafes with malware used to mine Siacoin (SC). It is claimed that the group managed to mine SC worth approximately $800,000. More than 100,000 Internet Kiosk Computers AffectedSince July last year, when the scheme is believed to have started, over 100,000 internet café computers have been infected with the malware. According to local Chinese media reports a network technician at JinHua, an internet café software firm, was the brains behind the illegal cryptocurrency mining scheme. The technician developed the cryptocurrency mining malware and it was subsequently installed by maintenance firms on internet café computers while routine checkups were being carried out. Proceeds from the illegal cryptocurrency mining exploits would then be split amongst the accomplices. While most cryptojacking malwares try to limit their activities and resource use in order to avoid detection, the JinHua malware was not throttled but was instead mining at full capacity. Concerns were initially raised last year in July after internet cafes in the Zhejiang Province city of Rui’an noticed that the processing speeds of their computers were becoming too slow. At the same time, the electricity bills of the internet cafes rose significantly all of a sudden. When consulted, the maintenance companies conveniently found nothing wrong with the computers. Malware Spreads to 30 CitiesWith no solution in sight and the internet café business becoming unviable, the internet kiosk operators then lodged a collective complaint with the police. The first arrest was made last year in October and so far 16 suspects are in custody. Two months before the Siacoin mining malware was discovered the cryptocurrency was trading at $ 0.002 but by July it was hovering around $ 0.01, an appreciation of 400%. At the time of writing Siacoin’s price was $ 0.013 with a market capitalization of more than $450 million, according to CoinMarketCap. Investigations on the matter are still ongoing. The malware has yet to be contained and has now spread to over 30 Chinese cities. More than 100 computer maintenance companies are suspected of being involved in the scheme