Editing Firmware (section)

== Firmware hacking ==
{{Main|Custom firmware}}

Sometimes, third parties develop an unofficial new or modified ("aftermarket") version of firmware to provide new features or to unlock hidden functionality; this is referred to as [[custom firmware]]. An example is [[Rockbox]] as a firmware replacement for [[portable media players]]. There are many [[homebrew (video games)|homebrew]] projects for various devices, which often unlock general-purpose computing functionality in previously limited devices (e.g., running [[Doom (1993 video game)|Doom]] on [[iPod]]s).

Firmware hacks usually take advantage of the firmware update facility on many devices to install or run themselves. Some, however, must resort to [[exploit (computer security)|exploit]]s to run, because the manufacturer has attempted to lock the hardware to stop it from running [[unsigned code|unlicensed code]].

Most firmware hacks are [[free software]].

=== HDD firmware hacks ===
The Moscow-based [[Kaspersky Lab]] discovered that a group of developers it refers to as the [[Equation Group]] has developed [[hard disk drive]] firmware modifications for various drive models, containing a [[Trojan horse (computing)|trojan horse]] that allows data to be stored on the drive in locations that will not be erased even if the drive is formatted or wiped.<ref>{{cite web|url=http://www.kaspersky.com/about/news/virus/2015/Equation-Group-The-Crown-Creator-of-Cyber-Espionage|title=Equation Group: The Crown Creator of Cyber-Espionage|publisher=[[Kaspersky Lab]]|date=February 16, 2015|url-status=live|archive-url=https://web.archive.org/web/20151202101934/http://www.kaspersky.com/about/news/virus/2015/equation-group-the-crown-creator-of-cyber-espionage|archive-date=December 2, 2015}}</ref>  Although the Kaspersky Lab report did not explicitly claim that this group is part of the United States [[National Security Agency]] (NSA), evidence obtained from the code of various Equation Group software suggests that they are part of the NSA.<ref>{{cite web|title=How "omnipotent" hackers tied to NSA hid for 14 years—and were found at last|author1=Dan Goodin|website=[[Ars Technica]]|date=February 2015|url=https://arstechnica.com/security/2015/02/how-omnipotent-hackers-tied-to-the-nsa-hid-for-14-years-and-were-found-at-last/|url-status=live|archive-url=https://web.archive.org/web/20160424062759/http://arstechnica.com/security/2015/02/how-omnipotent-hackers-tied-to-the-nsa-hid-for-14-years-and-were-found-at-last/|archive-date=2016-04-24}}</ref><ref>{{cite web|publisher=[[Daily Kos]]|url=https://www.dailykos.com/story/2015/02/17/1364910/-Breaking-Kaspersky-Exposes-NSA-s-Worldwide-Backdoor-Hacking-of-Virtually-All-Hard-Drive-Firmware|title=Breaking: Kaspersky Exposes NSA's Worldwide, Backdoor Hacking of Virtually All Hard-Drive Firmware|date=February 17, 2015|url-status=live|archive-url=https://web.archive.org/web/20150225044646/http://www.dailykos.com/story/2015/02/17/1364910/-Breaking-Kaspersky-Exposes-NSA-s-Worldwide-Backdoor-Hacking-of-Virtually-All-Hard-Drive-Firmware|archive-date=February 25, 2015}}</ref>

Researchers from the Kaspersky Lab categorized the undertakings by Equation Group as the most advanced hacking operation ever uncovered, also documenting around 500 infections caused by the Equation Group in at least 42 countries.