Android car head units hijacked by malware and pulled into hidden proxy botnet

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Kaspersky found Android malware abusing DoFun car head units via TWCore updates

Multi‑stage attack installs loaders and reverse proxy, aiming to build a botnet of connected cars

Campaign attributed to MoYu Group; DoFun patched vulnerabilities after disclosure

We’ve seen botnets comprising cameras and DVRs, we’ve even seen botnets comprising smart fridges and digital frames, but we’ve never seen botnets comprising automobile infotainment systems . First time for everything.

Earlier this week, security researchers Kaspersky warned about finding a brand new Android malware targeting the car’s head unit. The victim seems to be a Chinese manufacturer called DoFun. Head units from this manufacturer, built on Android, are running an app for analytics and software updates called TWCore.

According to Kaspersky, the attackers abused TWCore’s update mechanisms, instructing it to download a malicious APK. This malware is then placed in the app’s cache directory and installed by the legitimate com.tw.core package.

No active campaigns

The researchers said this was a multi-stage attack. In the first stage, a tiny dropper with no user interface gets deployed. It decrypts embedded data, and extracts the information it needs for stage two. In the next stage, the loader contacts the attackers’ server and gets instructions about stage 3, which can be different things, from deploying additional malware, to running the “zhima” reverse proxy.

Despite its multifunctional nature, Kaspersky believes that the true goal of the campaign is to assimilate the cars into a botnet. Some cars come with a SIM slot and are connected to the internet 24/7. It is probably not an exaggeration to say that cars just might be the perfect devices for a malicious botnet.

Kaspersky attributed the campaign to MoYu Group, a threat actor known for building malicious botnets based on Android devices. In the past, this group was observed building the BadBox botnet out of Android smartphones, tablets, streaming devices, and other internet-connected hardware.

The researchers notified DoFun of their findings, and the vulnerability was quickly fixed: "We notified the vendor about the distribution scheme, and they subsequently reported fixing the security issues," the researchers said.

Via The Record