Recruitment of Ivan Vanko
Justin Hammer took Ivan Vanko to the Hammer Industries Headquarters, having offered him an agreement of mutual colaboration to take advantage of the knowledge demonstrated when constructing the armor used to attack Tony Stark in Monaco. Hammer showed the multiple prototypes of an armor similar to the ones used by Stark as Iron Man. Vanko easily hacked Hammer's software, and stripped off the head of one of the armors, despite Hammer's warnings of its cost.
Vanko asked Hammer's intentions, that wanted to assure himself a position as the Department of Defense Primary Systems Contractor at the Pentagon for over 25 years, while humiliating Stark for his role in suspending his contract after revealing his attempts to create an armor before the Senate Armed Forces Committee Washington, D.C.
Vanko seemingly agreed with this plan, and for the next few days, he worked on improving Hammer's armors, transforming into Drones. Vanko managed to convince Hammer of the change as people may give problems, reluctantly accepting as he warned Vanko that the drones should be amazing.
Vanko was also secretly working in an improved armor for himself, and lied to Vanko saying that the Drones wouldn't be operative for the Stark Expo event, saying only a presentation would be available, but not a full demonstration. Infuriated, Hammer returned to his Headquarters, and given that Vanko didn't fulfill his part of the agreement, took away his belongings and custodied him with two security guards. Vanko easily killed the guards, and called Stark, threatening him to destroy him just as Howard Stark destroyed his family.
Raid of Hammer Industries
S.H.I.E.L.D. agent Natasha Romanoff coerced Justin Hammer into confessing the identity of the responsible of the attacks made by his Drones at Stark Expo, and Hammer told her that the responible was Ivan Vanko, and he was located at Hammer Industries Headquarters.
Happy Hogan accompanied Romanoff to Hammer Industries, and started fighting the first guard while Romanoff easily defeated the rest, clearing the path to Vanko's control room. Vanko, having been informed of the security breach, deployed the remaining drones and activated his own armor.
Romanoff found that Vanko was gone, rebooted the system to give Rhodes control of his armor, in time to avoid it killing Stark, and inadvertedly let Pepper Potts know of Stark's disease. Nick Fury ordered Romanoff to hack Hammer Industries mainframe to check the developments made by Justin Hammer, in order to take the worthy technology and destroy the rest before the authorities arrived.