But deeper analysis of applications has shown that data is sent unencrypted, and over HTTP, which means it is unprotected when it travels to the servers. Due to the absence of encryption, data can be intercepted by anyone – via unprotected Wi-Fi, by the Internet Service Provider or through malware on a home router. Worse still, the intercepted data can also be modified, meaning the application will show malicious ads instead of legitimate ones. Users will then be enticed to download a promoted application, which will turn out to be malware and put them at risk.
Kaspersky Lab researchers have examined logs and network traffic of applications in the internal Android Sandbox to uncover which applications transmit unencrypted user data to networks over HTTP. They identified a number of major domains, most of them part of popular advertising networks. The number of applications using these SDKs totals several million, with most of them transmitting at least one of the following pieces of data in an unencrypted way:
• Personal information, mostly the user’s name, age and gender. It may even include the user’s income. Their phone number and email address could leak too (people share a lot of personal information in dating apps, according to another Kaspersky Lab study)
• Device information, such as the manufacturer, model, screen resolution, system version and app name
• Device location
“The scale of what we first thought was just some specific cases of careless application design is overwhelming. Millions of applications include third party SDKs, exposing private data that can be easily intercepted and modified – leading to malware infections, blackmail and other highly effective attack vectors on your devices,” said Roman Unuchek, security researcher at Kaspersky Lab.
Kaspersky Lab researchers advise users to follow these measures:
• Check your app permissions. Do not grant access to something if you don’t understand why. Most apps do not need access to your location, so don’t grant it
• Use a VPN. It will encrypt the network traffic between your device and the servers. However, it will remain unencrypted behind the VPN’s servers, but at least the risk of leakage is reduced during the process