under cover of [sth], under the cover of [sth]exprexpression: Prepositional phrase, adverbial phrase, or other phrase or expression--for example, "behind the times," "on your own."
(concealed)
在…的掩护下 zài … de yǎn hù xià
打着…的幌子 dǎ zhe … de huǎng zi
Under cover of legitimate businesses, the Mob continued its illegal activities.