Symbols considered evil in some cultures include the horned hands, or cornuto, the pentagram, or inverted pentacle, the chaos symbol and the alchemical symbol for sulphur. Many of these symbols are presently associated with the occult and Satanism, though they may have had other previous meanings not connected with evil.
One example of a misunderstood evil symbol is the reversed cross. It is presently connected with Satanism, but was originally the cross of St. Peter, who refused to be crucified in the same manner as Jesus. Another example is the Black Sun. With decorative origins in medieval times, it became a symbol of Nazi Germany.
The horned hand, or mano cornuto, is actually a gesture to ward off the evil eye and did not initially have evil purposes. In the present day, it is seen as a Satanic symbol. The pentagram with the point up has a long association with Wicca and magic. However, it had other uses as the seal of Jerusalem and a symbol for the five wounds of Christ in the Middle Ages. In the present day, an inverted pentagram with the point straight down is an occult or Satanic symbol.
The eight-pointed chaos symbol has its roots in fantasy fiction and RPG games, but was also found in Aleister Crowley's tarot deck.