Idiom 成語 13

无孔不入 (wú kǒng bù rù) means:

English meaning:
to penetrate everywhere
to find every possible gap or opportunity
ubiquitous / all-pervasive
able to get into every crack or situation
Sense of the phrase:

It describes something that is so widespread or persistent that it can enter or influence any place or situation, often used for things like advertising, influence, gossip, or even negative forces.