Hailing from Virginia Beach, Virginia, Michelle learned very early on that she had a knack for computers. In high school, she used her school's computer system in conjunction with her own laptop to alter an enemy's grades enough that she was no longer in the running for Class Valedictorian in their senior year. She was never caught and felt justified of being able to ruin someone she felt was an uncaring braggart.
Michelle continued on this path by hacking into government files and manipulating the credit cards, social security numbers and bank accounts of low-ranking officials, causing them embarrassment when they'd go to write a check, only to find out their account had been overdrawn. She remained virtually undetectable until she stumbled upon the existence of the U.S. Army's experimental nano-mites that would later be stolen by
Cobra, while hacking another government system roughly one year before they were unleashed on the world. She was arrested for he past and present transgressions and sent to federal prison.
When it was later discovered that she knew about the existence of the nano-mites and possibly a way of stopping them, she was commissioned to work for the government instead of against it in exchange for an early release. As Firewall, she decided to turn her life around and along with Daemon, was appointed to the
G.I. Joe team on a temporary basis in order to combat the nano-mite threat.
In the IDW reboot series Firewall is a G.I. Joe liason with Flint's special unit running out if a casino in Las Vegas.