MediaTek

Researchers from Bitdefender have discovered that thousands of inexpensive Android devices are preloaded with malware called "Midnight Mimosa," which generates fraudulent advertising revenue. This malware is embedded in the device firmware before the first power-up, making it impossible for users to uninstall. It operates with system-level privileges, allowing it to install or remove applications without user consent and to download additional code. The malware primarily aims for financial gain through advertising and click fraud, while also gathering information about devices. Bitdefender has detected this malware on thousands of devices across over 150 countries, with the highest concentrations in Mexico, France, and Italy, followed by the United States, Germany, Brazil, and Spain. Many affected devices are low-cost, white-label, or counterfeit models, often sold online. The malware stealthily installs legitimate-looking applications that display ads in invisible windows, generating ad impressions without user awareness. Bitdefender identified at least 32 disguised applications and found 13 apps in the Google Play Store with similar ad-fraud code. The source of the malware remains unidentified, but some affected firmware was signed with certificates from Shenzhen Zediel, a Chinese company. The researchers suggest that the malware could have been introduced at various stages of the supply chain, potentially by manufacturers or intermediaries.