SHANGHAI — A Chinese woman was detained by authorities for “spreading pornography online” after she posted a homemade pornographic video to the Web, according to a report by the public security bureau.“Anyone who films, uploads or distributes such videos is guilty of disseminating pornography,” Beijing lawyer Lu Heping told China Daily.

Authorities sought the woman, identified only by the surname Huang, for nearly seven months before the arrest. She posted the 12-minute solo clip to a blog in late October under the title “Kappa girl at Shanghai No 1 Department Store’s east building.”

The blog was thought to belong to someone surnamed Lu. Authorities determined Lu was a pseudonym for Huang, whom they were able to track through her employment at the department store.

The video might not have attracted the attention of police, except that it quickly became one of the most popular downloads on the mainland. Based on that popularity, “Lu” began offering advertising space on her blog at the price of 30,000 yuan per ad appearance.

Authorities now are seeking a man who is suspected of feeding traffic to the video.