The Swedish striker gave Villa a seventh-minute lead against the third division outfit after good work from Lee Hendrie down the right, Juan Pablo Angel doubled the lead shortly into the second half and then set up Allback's second.
Ulises de la Cruz grabbed Villa's fourth goal and the winger's cross allowed Allback to complete his second pre-season hat-trick 10 minutes from time.
Villa: Enckleman, Mellberg, Alpay, Johnsen, Samuel (Jackman), Hendrie (De la Cruz), McCann (Davis), Barry, Whittingham, Allback, Angel (Vassell)