Maya Hansen is one of the most respected and well known bio-technologists in her field. She developed her notoriety through her work at reprogramming the repair center at the center of the brain. It was during one of conferences that she first befriended a young Tony Stark.
As the years passed Maya's breakthrough research afforded her the ability to work on the development of the next Super-Soldier formula, which a generation ago had created Captain America. Her approach was to exploit the genetic potential of man through nano-tech and in this vain she eventually developed Extremis.
Extremis was meant to "hack" into the body's repair center and recode the human genes with a more advanced version, leaving the host with improved organs and super powers.
When she learned that she was going to lose funding, Maya came up with the idea that if she could get a test subject to fight and conquer Iron Man, she would be able to prove it's potential. It was with this logic that she stole Extremis and put it into the hands of terrorists, who quickly injected, Mallen one of their own. As the next step in her plan, she contacted Tony Stark feigning distress to ultimately maneuver him into a confrontation with the Extremis-enhanced terrorist.
Tony Stark is eventually able to stop Mallen with Maya's help by becoming Extremis-enhanced himself. Following this, Maya is sent to prison for her action. It is there that a relative of one of Mallen's victims slices her left cheek leaving a nasty scar. Before any further damage could be done Maya is broken out of jail by Iron Man in roder to help him determine how he is being controlled to assassinate specific targets. Through her loyal work, Tony Stark uses his position as Director of SHIELD to commute Maya's sentence and have her placed under his custody. While working for Tony, she is prohibited from pursuing any further research into Extremis, due to Tony's belief that is was far too dangerous. Maya and Tony quickly become romantically involved and she moves in with him.
During this period there was a tragic incident involving Extremis that could have been prevented had Maya been allowed to continue her research into Extremis. As a ward of SHIELD, she is unable to perform this research, so she feigns her own death and accepts an offer to work for a secret organization called Prometheus Genetech.
Unbeknownst to anyone involved, the Prometheus project is actually backed and run by the Mandarin in disguise. His plan was to wipe out the majority of the human race using an airborne version of Extremis which Maya was working on. Despite her ignorance of Mandarin's plan, Maya built into her aerosol version of Extremis a programmed cell death (PCD) which only she could deactivate.
In order to launch the aerosol Extremis, the Mandarin needed to obain the PCD deactivation codes and to do so, he created the illusion of Tony Stark begging her for the deactivation codes, which she eventually gave him. Despite the Mandarin releasing Extremis into the air, Stark was able to stop it from spreading and to resue Maya.