The Maverick Virus, also known as the Irregular Virus, is a volatile computer virus that corrupts the sentient robot species Reploids and their giant less intelligent automations called Mechaniloids to go "Maverick" as dubbed by their 22nd century human creators, hench this gave rise to the hostile Reploid culture known as "Mavericks. A new computer bug surpassing the Maverick Virus is
This renegade digital program has the power to infect and corrupt its targets. The Maverick Virus itself is quite selfsame for it cause hostile and criminal behavior within Reploids alone, it also can make Mechaniloids go berserk with its ability.
Also, on its own, it can make Reploids go berserk.
Once corrupted, the Sigma Virus is unrelenting and the infected cannot be easily returned to normal. Only when the host itself has died does the Maverick Virus die along with it. Therefore, the only option for most vitiated Reploids is to be "retired" by the Maverick Hunters.
At some point after the end of the X series, a cure for the Sigma Virus/Maverick virus was developed in the form of the Mother Elf program.