Firewall

The film opens with Jack Stanfield (Harrison Ford) leaving his content, loving wife Beth (Virginia Madsen), two children, and a beautiful house to go fulfill his duties as Vice President of Security at Landrock Pacific Bank in downtown Seattle (actually shot in Vancouver, British Columbia as was most of the film). The day goes smoothly until Jack is visited by a collection agency, claiming that he owes $95,000 in debts to their online gambling site. He trusts a fellow colleague to take care of it (as he is convinced of some form of identity theft) and goes out for dinner with colleague Harry and potential employer, Bill Cox (Paul Bettany). After the meal, Harry leaves in a taxi and Jack gets in his car. Unexpectedly, Cox follows him into the back seat. Cox then goes on to tell Jack that his family is being held hostage at their home to ensure Jack's cooperation. He then points a gun to Jack's head and forces him to drive home.Upon their arrival, Jack sees that, although his family is unharmed, they are under heavy watch by Cox's henchmen. Jack is not told what to do until the next morning, when he is told that he must give Cox $10,000 each from the bank's 10,000 largest depositors ($100 million total). He is outfitted with audio and video devices in the form of a pen and a body microphone, making any intentions to resist useless.Once at work, Cox makes a surprise visit, reintroducing himself as Bill Redmond. Next, Jack gives him a tour of the facilities and security system. On the way back home, Jack attempts to bribe a henchman into betraying Cox, yet this only results in Cox killing the man. The Stanfields attempt an escape, but the plan fails just barely. In retaliation, Cox tricks the Stanfields' son Andy with a cookie containing nut products. Because he's allergic, Andy goes into anaphylactic shock. Cox withholds the treatment, (an EpiPen) until Jack acquiesces to their plan.The next day, Cox forces Jack to fire his secretary Janet Stone fearing she is growing suspicious. Jack downloads the files for the $100 million onto his daughter Sarah's iPod mini hard drive and then initiates a wire transfer to send the money to Cox's offshore accounts. Before leaving, Jack uses an employee's camera phone to take a picture of the account information on the screen. Cox then sets about wiping his tracks clean, deleting security data and surveillance tapes and using a virus to put the network on the entire building into disarray, setting Jack up to take the fall for embezzlement. Returning home, Jack finds the house empty except for Liam, one of Cox's men.Realizing Liam is still around for no reason other than to kill him, Jack turns to survival instinct; he pushes Liam over a chair, grabs a heavy glass blender, and viciously beats him in the head with three blows, killing him. He then tries to call Harry using Liam's unmonitored cell phone but cannot reach his friend. Instead, he sneaks into Harry's apartment to wait for his friend's return. Both Cox and Harry enter. Cox suddenly shoots Harry from behind, using the gun he had earlier confiscated from Jack. Because of this, along with a message planted on Harry's answering machine earlier by Beth as she is held at gunpoint, it appears that Jack killed Harry in a jealous rage over Beth.Jack runs to the only ally he has left: his "fired" secretary Janet. He asks her for help, and she provides him with transportation to a late-night branch of the bank at Seattle-Tacoma International Airport. There, he uses the picture from the phone he took earlier to get access to Cox's account and calls him. Jack tells him that theres been a change of plans: he has hacked into his Cayman Island accounts and is stripping five accounts, $20,000,000 apiece. Cox tries forcing Jack to put the money back, but it is a futile threat. Jack informs Cox that he will get his money when he gets his family. Next, Jack tells Cox that he will call him when the banks open to make the exchange before hanging up on him. During the conversation, Jack hears the family dog in the background, and realizes that the family can be located and followed by the GPS tracking unit in the dog's collar. This leads him and Janet to an abandoned house. He leaves Janet on the road to call the police.Cox shoots one of his own henchman (Vel) who had compassion for the hostages and removed the Stanfield's tape gags after Andy begins to suffocate because he is unable to breathe properly with the tape gag over his mouth. Another henchman (Vince Vieluf) chases after Sarah, Jack runs into the chaser with Janet's car, hurling him into an RV, which then explodes, burning the RV, killing him and destroying Janet's car. Cox, seeing that the tide is turning against him, panics and takes Beth and Andy to the upper level of the house. Jack scales the side of the house, destroys a window and comes to rescue his wife and son, tackling Cox to the floor and forcing him to a final showdown. After a long and grueling struggle with Cox, Jack finally gains the upper hand, impaling him through the back with a pickaxe, and wins his family's freedom.

Question: Who did Jack struggle with?
Answer: Cox.