North Korean hackers are hiding malware in “copycat applications” that look like they are South Korean to steal personal information of users and other sensitive data, the national spy agency said Friday.

The National Intelligence Service busted the apps, which were made and distributed by a North Korean hacker ring and “nearly identical” in designs and features to a popular South Korean site. The spy agency only identified the site imitated in the North Korean phishing attack as an e-commerce platform that has about 20 million users in South Korea.

To avoid such North Korean-made phishing apps, the NIS recommended downloading apps only from official stores, and installing anti-virus software and updating it frequently. If infected with malware, a device can become vulnerable to data theft and manipulation, the spy agency said. The agency added that no harm has been detected so far.

In June, the NIS warned North Korean hackers created a phishing page that resembles the South Korean portal Naver to steal user name and password combinations, and possibly other online credentials.