Du'a for concealment and protection

اللَّهُمَّ اسْتُرْنَا فَوْقَ الْأَرْضِ، وَتَحْتَ الْأَرْضِ، وَيَوْمَ الْعَرْضِ

Allahummasturna fawqal-ardi, wa tahtal-ardi, wa yawmal-'ard

O Allah, protect and conceal our faults while we are on earth, under the earth, and on the Day of Presentation.

A general supplication, not a narration from the Prophet (peace be upon him).