2005 Malibu Maxx/ Brakes sticking ?

Yes it could, unless it's braided line. But if its black/rubber to look at then it has a really smalll fluid passage and over time you can get inner deterioration and the wall breaks down. It sort of makes a valve which doesn't release the pressure. You could try just taking off the brake caliper...2 bolts usually and have someone pump the brake pedal slowly one at a time on your count. You should see both pistons move out a bit. If not clamp the one that moves and try and pump out the jammed one to clean the piston. Don't pump it out too much or the piston will pop out! and you will have to bleed the fluid all through. No more than a cm. If it's really jammed then the fun begins....