The amount of apps containing malware has increased by 216 percent between June and August, compared to the previous three month period, with China-based app stores being the most at risk, according to mobile security company TrustGo.

According to the company’s summer Mobile Mayhem report, the amount of malware-infected apps from a sample of 1.7 million apps in 175 marketplaces around the world grew from 11,822 to 25,580 during the period.

A third of apps flagged as malicious, high risk (contain code that create security risks) or low-risk/noisy (could annoy users with excessive notifications and ads) were found in China-based app stores.

The riskiest app store was found to be China’s Anzhi, with a 63 percent risk rate, according to TrustGo, while Europe’s Aproov was the safest at 2 percent. Google Play was ranked as the fifth safest marketplace despite hosting more than 90 malicious apps.

One out of six apps around the world were categorised as high risk with games the most likely to be infected and social media and productivity apps found to be the least risky.

TrustGo founder and CEO, Xuyang Li, said that with many Chinese users unable to access Google Play, a large number of third party domestic marketplaces have emerged. However, a lack of controls to prevent bad apps being made available has made Chinese app stores particularly insecure.