Consisting of a clenched fist with the second and fifth fingers straightened out, the corna (‘horns’) hand gesture has most recently been adopted by fans of rock and heavy metal music, first used by Black Sabbath vocalist Ronnie James Dio. The gesture carries only a vague meaning, implying the presence of Satan, malevolence
and loud guitar music, and is used in much the same way as headbanging. The gesture was actually popularized as a Satanic salute during the 1960s, appearing in many editions of the Satanic Bible. Nowadays many Americans use the gesture simply to mean “rock on”, or in support of the University of Texas in Austin (known as the “Hook ‘em Horns”).

Occasionally used by baseball players to indicate “two outs”, the corna is actually a positive hand gesture in Buddhism and Hinduism, known as the Karana Mudra in such circles, and is used to dispel evil – an interestingly opposite meaning to its contemporary significance.
Does one want to take it as a 'symbol of Devil' or 'a symbol that protects from the evil', remains a personal choice. So chose whichever you feel comfortable about. My job here is to reveal some hidden or not very commonly known points. Whatever one believes in, remains a personal choice.