the descent of rootkits

i think it's about time to get to the root of the rootkit terminology shift...

i've blogged before about what i think a rootkit is, and about how the anti-spyware coalition's definition is basically in line with my own...

and yet somehow the definition currently in use is all about hiding processes and/or activities from the user rather than about root/administrative privileges...

as i observed before; f-secure, despite acknowledging that the original unix meaning was basically in line with the one i use in this little blurb:

The term rootkit is very old and is dated back to the days when UNIX ruled the world. Rootkits for the UNIX operating system were typically used to elevate the privileges of a user to the root level (=administrator). This explains the name of this category of tools.

still insists on using the new hiding-related definition...

but my first clue about where this new definition came from was in mark russinovich's blog entry where he gives his definition:

Software that hides itself or other objects, such as files, processes, and Registry keys, from view of standard diagnostic, administrative, and security software.

which he says he derived from what the rootkit developer community was using as a definition and which happens to basically mirror the definition proposed by greg hoglund, founder of rootkit.com (a hub of the aforementioned developer community) and author of a book on these so-called rootkits (not that registering a domain and/or writing a book actually makes anyone a credible authority, but for the sake of argument lets say he is one), which states:

A rootkit is a tool that is designed to hide itself and other processes, data, and/or activity on a system.

a rootkit developer community? well, a community of developers of cloaking technology at any rate... but lets think about this for a sec... by and large, these developers are not going to be a malicious bunch (there are far more good people in the world than there are bad) so when they look at rootkits, even the original unix-style rootkits, they aren't going to really be all that interested in the more blatantly malware type features - the thing that's going to interest them is the cloaking because it has applications outside of malware...

it has been suggested that terminology changes with frequent misuse and that is most likely what happened here... the developer community in question, lacking any significant influence from malware experts (since malware issues were outside the scope of their interests, and because malware expertise is a lot harder to come by than you might think), used and reused the term rootkit (since rootkits represented examples of the kinds of sophisticated stealth techniques they were interested in) so much outside of it's original meaning that they gave it a new meaning...

so what? you might well think that language changes in just this way so there's nothing wrong here, but consider this:

• technical jargon does not evolve the same way that conversational language does... imagine if people started using the term 'telescope' to refer to something completely different...
  
• hoglund's definition describes what is more properly known as stealth in the malware field... the concept of stealth has enjoyed wide use in the malware field for at least the past 20 years (back in 1986, the brain virus wasn't just the first pc virus in the wild, it was the first stealth virus) and has been applied to virtually all forms of malware, not just rootkits
• stealth is actually a more natural and intuitive label for what hoglund's definition describes; so much so that the term is creeping back into the vocabulary of the rootkit community at rootkit.com to cover new types of cloaking that 'rootkit' is no longer felt to encompass
• under hoglund's definition, the term 'rootkit' has no etymological basis - that is the word doesn't appear to come from anywhere or be rooted in any underlying details... by comparison, a collection of programs (-> a collection of software tools -> a toolkit -> a kit) that aids in gaining or maintaining root/administator (administrator is called 'root' in unix) access is fairly clear about where the term 'rootkit' comes from

while upcoming concepts like 'stealth by design' indicate that the current terminological misstep may be in the process of correcting itself, there will be purists who will resist the change in terminology on the basis that the proposed new definition of rootkit is not what a rootkit was supposed to be... they'll simply have to be reminded that their rootkit definition was not the original one either and if the correction does take place it will simply be a reversion to the original state of things...