Evil Twin

Evil Twin is protection, anti-IC program is another viscious program written by Ware Wolf, using a similar structure as Black Sky. This program is a powerful one-two punch designed to offer maximum offensive and defensive capabilities to a netrunner. Evil Twin can first be intiated as a protection program, receding the netrunner's signal so that it is harder to lock onto (has same effect as Force Shield and Reflector). From this stage it immediately intiates its counterattack capabilities, tracing the attack and striking at the attacking deck/datafortress (same effect as Krash).

In game terms, this means that Evil Twin can: 1) defend the netrunner from attack, then attack the attacker with a +2 deck speed; 2) attack an enemy system and be kept ready to protect the netrunner and his programs from attack with a + 2 deck speed; 3) act as a protection program only or as an attack program only, but with no intiative bonuses. Has Auto Re-Rezz.

Source

 * Chromebook Volume 3, pg.76