[DigitalToday reporter Chi-gyu Hwang] AhnLab said on Tuesday it found many apps on official app stores (the Google Play Store and Apple App Store) that pose as offering practical, everyday information while exposing users to excessive advertising, and urged users to be cautious.

According to AhnLab’s analysis, the apps attract users by claiming to provide information and news on topics with high user interest such as government policies and subsidies, IPOs and loans. In actual use, they operate by showing ads excessively and repeatedly.

They are designed to display ads every time the screen changes and to allow the ads to close only after a set time has passed or after the user clicks on them. AhnLab said they are presumed to have been made to generate high advertising revenue. It said the developer appears to be producing mass-made apps of a similar type and continuously distributing and updating them by circumventing app store registration policies to maintain this revenue structure.

With user reviews dominated by negative opinions due to such inconvenience, some positive reviews were found to repeat similar wording. AhnLab said they are presumed to have been artificially written using stolen accounts.

AhnLab said the apps, due to structural characteristics that allow the insertion of many ads, were analysed as being a form that could easily add other malicious functions such as downloading and running malware. It said this could lead to various types of damage, including theft of personal and financial information, call hijacking, access to the camera and keyboard, and leakage of photo and video files, and stressed that special caution is needed.

Jang Yeon-cheol (장연철), a manager on AhnLab’s engine development team who analysed the case, said, “Even on official app stores, unclear apps that cause user inconvenience through excessive advertising, or that could later add malicious functions, are being steadily found.” He added, “Therefore, even when using official app stores, users should thoroughly check an app’s reputation, including user reviews and developer information, and make a habit of running mobile antivirus scans.”