lurk 
/ˈlɚk/ verb
lurks; lurked; lurk·ing /ˈlɚk/ verb [no obj] 1 : to be in a hidden place
▪ The cat was lurking [=hiding] behind the sofa. : to wait in a secret or hidden place especially in order to do something wrong or harmful ▪ She could tell there was someone out there lurking in the shadows. — often used figuratively ▪ Trouble lurks around every corner. ▪ There is tenderness that lurks underneath his tough appearance. ▪ Who knows what evil lurks in the hearts of men? ▪ The idea had been lurking in her mind for some time. 2 computers : to read messages written by other people on the Internet in a newsgroup, chat room, etc., without writing any messages yourself
▪ The cat was lurking [=hiding] behind the sofa. : to wait in a secret or hidden place especially in order to do something wrong or harmful ▪ She could tell there was someone out there lurking in the shadows. — often used figuratively ▪ Trouble lurks around every corner. ▪ There is tenderness that lurks underneath his tough appearance. ▪ Who knows what evil lurks in the hearts of men? ▪ The idea had been lurking in her mind for some time.
— lurk·er noun, plural lurk·ers [count]
