Showing posts with label mobile malware. Show all posts
Showing posts with label mobile malware. Show all posts

Sunday, February 12, 2012

is the iphone really malware free?

friday morning mikko hypponen posted a tweet about the folks behind flexispy changing the look of their site, and i took the opportunity to pose a question to him about iphone malware. you see, flexispy is (or was) a piece of mobile malware that f-secure posted about about 6 years ago. not only that, but there's a version of the software for the iphone, so i found mikko's repeated statement that there was no malware for the iphone to be a little strange in light of the fact that both he and his company have been aware of software that seems to contradict that claim for quite some time.

the resulting discussion with both mikko and his colleague sean sullivan lead in 2 separate directions, so let's look at them in turn. first mikko responded with the following:
@imaguid No malware for iPhones. If you jailbreak your phone: all bets are off. Flexispy runs on jailbroken only.
now to me, this gets to one of the hearts of the matter. when people say there's no malware for the iphone, they're only talking about non-jailbroken phones. the pertinent difference between a normal iphone and a jailbroken iphone is that normal iphones can only install apps from the app store. the app store is a so-called walled garden where all the apps go through a screening process to keep out undesirable programs.

so what people really mean when they say no malware for the iphone is that there's no malware in the app store. this is an important distinction, because the iphone ecosystem (and by extension, the threat landscape) extends beyond the app store. when chris di bona attempted to downplay the threat malware played to android devices by pointing to google's efforts to keep their android marketplace clean, a number of folks were quick to point out that the android ecosystem extended beyond google's android marketplace, so it seems strange that people would forget the same line of reasoning applies to the iphone as well.

one other thing (well, the only other thing, really) that mikko said was:
@imaguid ...and to top it all: we couldn't do anything about iPhone malware anyway, as Apple won't allow Antivirus products to iPhone.
and you know what? why should they allow them when there's apparently "No malware for iPhones"? whether or not there is malware for the iphone, apple doesn't want people to think there is. there is this (rather old) idea that computers can be as easy to use as an appliance (like a toaster). this idea is actually very appealing. it promises computers that just work, computers that don't get malware, computers that are easy and safe and worry free. that promise is part of the secret sauce behind apple's marketing, but if they allowed AV products in then it would dispel the illusion of the appliance computer and apple's products would lose their lustre. it's very convenient, then, that AV vendors are willing to be complicit in apple's marketing by repeating the claim that there's "No malware for iPhones".

but such unqualified claims are, as mikko has revealed, not technically true. it's not that there's no malware for iphones, it's that there's no malware in the iphone app store.

but wait, is that really true? is there no malware in the app store at all? i'm not sure that's true when we've recently been made aware of apps in the app store that collect and send personal information to a remote server without the user's knowledge or consent. but it's about time i turned my attention towards the much more verbose and nuanced discussion that sean sullivan and i had on the subject. perhaps he can shed light on why these personal info stealing apps shouldn't be considered malware. while mikko didn't question the classification of flexispy as malware, sean informed me that f-secure no longer calls it malware.
@imaguid @mikko But they then added an installation interface, and we have since categorized it as riskware.
that's right - in spite of the fact that it is designed and marketed as a tool for spying on other people, it is not classified as spyware or malware because it was given an installation interface - meaning that the attacker has to have physical control of the phone for at least as long as it takes to install an app. now, on the desktop this might be a meaningful mitigating factor, but on mobile devices where physical access is so much easier to achieve? come on...

why exactly that stops it from being malware in general or spyware in particular in the context of mobile device security i still can't fathom, but sean offered up two things by way of explanation. one being a concern over being sued... by malware vendors. this rationale is something i heard from dr. solomon years and years ago, but i have to admit i had hoped that the industry had become less spineless in the interim. i guess that was too much to hope for. google may stand up to the government on behalf of it's users (perhaps not always, and perhaps it doesn't always succeed, but it has tried), but apparently anti-malware vendors only stand up for their users when there's zero risk they'll be challenged.

the other thing he offered was the following definition of spyware from google:
Software that self-installs on a computer, enabling information to be gathered covertly about a person's Internet use, passwords, etc.
apparently it's not enough that the software spies on you in order for it to be called spyware, it has to "self-install" as well. now i'm sure i must be missing something, because this definition seems to exclude anything where the victim is socially engineered into installing the software (it's hard to call it self-installing if the victim is the one installing it). it also seems to exclude anything that utilizes the particular trojan horse case where the software actually does perform the function it claims to, so the payload is additional functionality instead of strictly misrepresented functionality. a game that also steals passwords, a text editor that also sniffs network traffic, webcam software that just happens to send the video stream to a second undisclosed location in addition to the intended recipient - all of these are examples of software that ought to be called spyware but which the victim actually knowingly installs (because the undesirable functionality is unreported) and thus fails to meet the "self-install" criteria. this is precisely the type of situation users of the photo sharing iphone app called path faced.

now, sean also pointed me towards the anti-spyware coalition's risk model description document. i had hoped it would help me to learn more about this "self-install" concept that sean assured me was part of an industry agreed upon standard definition. things didn't turn out that way, since the term "self-install" doesn't appear in that document, but the topic of installation and distribution do figure prominently in the contexts of both risk factors and consent factors. unfortunately this document from 2007 appears once again to be geared to desktop computing rather than mobile computing. that's probably not too surprising considering it's 5 years old now, but it does highlight the age old problem of letting context into the classification process. mobile devices are easier to gain illicit physical access to, as well as being shared more freely (and more frequently) in social circumstances by their owners. the issue of consent at the point of install has far less significance as a risk mitigation for mobile devices. furthermore, the issue of consent at the point of install pretty clearly drops the ball in the case of trojans because it's not necessarily fully informed consent.

as the risk model description document demonstrates, somewhere along the line the industry gave up on basing it's classification system on functional definitions. sean insists that this is a "stricter process" but i think it's more correct to say that it utilizes more criteria than a functional definition system would. utilizing more criteria doesn't always lead to a stricter process because not all criteria are created equal and, at least in the case of the risk model description document, some of those criteria are used to create exceptions (which are generally not the hallmark of a strict process).

one of the last things sean wondered is how could the AV industry possibly use my (supposedly) broader definition(s) and not be accused of FUD. now, aside from the fact that the industry is already accused of FUD (and worse) pretty much regardless of what they do, i think it's important to spell out one of the key differences between a functional definition and the kind of definitions that sean sees in use. definitions that include contextual evaluation are judgements, they engender choice and leave room for agendas. a functional definition has no judgement, it is purely descriptive of the functional capabilities of what is being classified. you can no more be blamed for saying software that spies is spyware than you can for saying water is wet or the sky is blue. there's no silver bullet to make accusations go away, but if you take judgement out of the equation it should render those accusations baseless.

so why is all of this important? because it appears that we've somehow stumbled upon a way in which malware can be classified as "riskware" instead of malware. nobody hears about the riskware classification, nobody cares. they hear "No malware for iPhones" and they shut the rest out because that's all they needed to know (or at least according to traditional notions of malware that should have been all they needed to know). classifying malware as something other than malware seems to be what's enabling people to make the "No malware for iPhones" claim, like some kind of terminological shell game. "No malware for iPhones" makes people think the devices are safe and worry free, but there are risks, and not just for those who jailbreak."No malware for iPhones" is creating a false sense of security and with the revelations that have been made about apple's abject failure to lock down a particular type of personal information and the near ubiquitous exploitation of that failure by app developers, it seems like the stuff of snake-oil.

i tend to think that when people face risks they want to know about them rather than be told there's nothing to worry about, and i tend to think that when those risks come in the form of software that acts against the user's interests, informing the user is the AV industry's job. some people don't want that to happen, they want their own interests to take precedent. if the AV industry allows that to happen through inaction (or worse, facilitates it) then they don't deserve the reputation they have for protecting the user. the industry may not be able to put AV software on iphones yet, but they can certainly do a better job of raising awareness of the risks than going around telling people there's "No malware for iPhones". maybe when public awareness is raised apple will change their ways.
image from secmeme.com

Wednesday, March 21, 2007

more mobile malware madness

y'know, there are times when i'm not really a big fan of repeating myself (like when it comes to garbage masquerading as insight) but when a supposed top security [/straight face] influencer [straight face] takes a piece of techdirt trash at face value (what's next? will we be citing crackpot, errr, slashdot as an authoritative source?) what's a malware guy to do?

(if this is sounding angry it's because i finally had to unsub from techdirt a little while ago after discovering how inaccurate it is even outside the malware field)

taking the false claims and misrepresentations from the top:
  1. f-secure spreads mobile malware FUD - see my previous post on the subject...
  2. kaspersky spread FUD about the mobile malware threat - in the original article the kaspersky folks make it clear that you may well not be very likely to see mobile malware in your home country... the dependence on the regional market penetration of susceptible devices (smart phones) on the extent of the risk has been well established..
  3. kaspersky took a news crew into a faraday cage in order to make them understand that mobile malware was a real threat - no, they took them in the faraday cage to demonstrate how cabir works...
  4. cabir is only a threat when you intentionally ignore the warnings - this is the oft cited yes/no prompt that people consistently think should mitigate the mobile malware threat even though it has been well established that the 'no' button doesn't work (the worm just sends itself again immediately so the prompt comes back as soon as you hit 'no'... if you need to make a phone call your only real options are to hit 'yes' or get out of range of the other infected device because you can't use the phone while the prompt is there)...
  5. kaspersky has suggested that mobile malware is common - again, read the original article, you'll find they don't make that claim at all... they do say that there are certain geographic locations where it's more common than others, though...
  6. kaspersky could have just found someone with the virus instead of taking the news crew inside a faraday cage - yeah, an anti-virus company is going to demonstrate the functioning of a piece of malware that is epidemiologically equivalent to an airborne biological pathogen without the protective measures necessary to keep it from spreading beyond their control... now pull my other leg...

Monday, July 24, 2006

cutting through the mobile malware mess

techdirt, renowned for it's technical acumen (in other words it's signal to noise ratio is just slightly better than the garbage heap of the internet known as slashdot), has a post today that basically roasts f-secure for spreading mobile malware FUD... small problem - i couldn't find the FUD even after following all their links to supposed examples...

let's take a closer look, shall we?

from silicon.com:
Sal Viveros, wireless security evangelist at McAfee, said F-Secure's figures are largely in line with industry figures in terms of the total number of mobile viruses but added such viruses have largely been "proof of concept" to date and pose little threat to users.
ok, so we've got independant verification of f-secure's figures on the total number of mobile malware instances - score 1 for f-secure...

from a different article on silicon.com:
"The number of proof of concept viruses is increasing but that's not to say there has been an increase in the risk of infestation or that there is any need for panic or worry."
the person making this statement (david wood of symbian, the company holding the largest stake in the mobile phone market - aka the microsoft of the mobile phone market) clearly doesn't understand the nature of risk... the more instances of malware out there the greater the chance of a particular user encountering one of them, and therefore the greater the risk...

from the same article:
He added that these viruses will only spread with user permission and conceded that in very rare instances a user could contrive to infect their phone.
which shows that he clearly doesn't understand what's really going on in a mobile infection scenario... the no option doesn't work - you choose no and the prompt just comes back... press no again and the same thing happens... cabir and similar worms will just keep trying and effectively DoS the phone until the user chooses yes... user interaction is a non-issue if the user isn't given a real choice...

(see the video evidence here, it starts about 26 minutes in)

[edit - there's a better view of the video evidence here, starting at about 1 hour and 26 minutes]

from an article at vnunet.com:
"Phone viruses so far have been spreading over Bluetooth, so they only affect phones that are within a few metres. A MMS virus can potentially go global in minutes, just like an email worm," warned F-Secure's antivirus laboratory.
now that is a little troubling that it says minutes - because mikko hypponen, in the video referenced above, says 24 hours (both for mobile phone viruses and for email viruses) and he explains why... it's correct that it has the same potential speed as email worms but minutes seems like an error, either on the f-secure rep's side or (more likely, since they're known for botching these sorts of things) the reporter's side...

at any rate, saying a type of virus has the potential to do X is quite a bit different than saying a particular virus will do X or is likely to do X (which is the implication techdirt makes here)...

and from the a zdnet.co.uk article that triggered the current threat at techdirt:
"F-Secure is saying there's a huge risk of malcode spreading, but they've built this up," said Simon Perry, European vice president of security for CA. "If you look at their behaviour, they've consistently pushed this message. But it's a theoretical, not a real threat," he added.
i don't know where mr. perry is getting this - mikko hypponen (again in the video referenced above) made it seem pretty clear to me that mobile viruses are not anywhere near as problematic as their pc counterparts... susceptible phones are comparatively quite rare, and most of the malware can only spread to other phones that are physically nearby... that doesn't sound like a huge risk to me... he does mention some big total numbers (in the tens of thousands) but considering the law of large numbers as it applies to this situation that doesn't really raise eyebrows...

furthermore, in the same zdnet article an f-secure representative is quoted:
"I have difficulty understanding how this can be bad for [the antivirus] business. This is not a mass problem for all consumers, but our solution is available to those who need it, and there are people who need it today," Impivaara added.
it seems hard to imagine how f-secure could be making mobile malware out to be a huge risk when they're quoted in the media as saying the opposite...

still, techdirt has persisted in laying the FUD spreader charge against f-secure for some time now, not unlike many other community sources (slashdot and digg are the 2 glaring examples) have done to many other vendors... it bears a striking similarity to the reaction you get whenever you suggest there are genuine security risks in mac osx or linux... i thought at first it might just be one site or 2 sites, but the pattern that is emerging seems more widespread - it seems to have something to do with the wisdom of mobs where the wisdom of crowds fails due to the signal to noise ratio being too low... the reality is is that he who yells loudest has the most individual impact on the whole and without sufficient real wisdom to counteract that impact the whole becomes an ignorant mob...