Then one of the twelve, called Judas Iscariot, went unto the chief priests,  And said unto them, What will ye give me, and I will deliver him unto you? And they covenanted with him for thirty pieces of silver.  And from that time he sought opportunity to betray him. (Matthew 26:14-16 [KJV])
Someone can be your personal Judas. You can have experienced multiple personal Judas in your life. A Judas is someone that seeks an opportunity to betray you.
Someone who tries to earn favor with authority by delivering you onto them.
How should we deal with a Judas ?
We should flee from him.