AhnLab Inc., South Korea's largest computer anti-virus service provider, said Friday that its latest smartphone security application has surpassed the 4 million mark in cumulative downloads.

AhnLab said in a statement that the "V3 Mobile Security" app, which is designed for Android-based smartphones, reached the download milestone on Tuesday.

The free-of-charge security app also placed fifth in the popularity rankings of overall applications available on Google Play, the company added. Launched in January this year, the V3 Mobile Security is designed to detect malware, protect privacy and optimize memory.

"Interest in PCs and smartphones has been growing in the wake of the recent ransomware attack," an AhnLab official said. "The app seems to have attracted users because of its security and convenience."

Ransomware refers to malware that locks up files on a computer with encryption until the victims pay a certain amount of money to hackers.

AhnLab was founded by Ahn Cheol-soo of the centrist People's party, who unsuccessfully ran in the May 9 presidential election. (Yonhap)