A quick guide to mobile malware (part 2)

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This is the second article in a 3-part series on mobile malware.

Why (should I be worried)?

Worm:iOS/Ikee.A changed the phone's wallpaper

Last week I gave a brief summary of the kinds of threats a user might encounter on the smartphones of today. This week’s article is supposed to cover the reasons why a user would worry about mobile malware, so let me give the short answer now:

Usually, mobile malware attacks are motivated by: Bragging rights; money; stealing personal information that can be sold for money. For the user that gets hit by the malware, it means: Losing control over your phone; losing your money; someone else might be using your personal details for who-knows-what.

So let’s assume your phone’s been infected. Just how much should you be worried? Well, that kind of depends on your luck and what kind of malware you’re dealing with.

“Hey folks! Look what I can do!”

Like PC-based malware, the first threats to appear on the phone are often the product of some technically-minded person finding a loophole in the phone’s operating system, writing a program to exploit it, then releasing it to the general public to, basically, prove that it can be done. A prank for bragging rights, more or less. There may also be more subtle motivations involved, but if your phone is on the receiving end, you probably wouldn’t care.

Sometimes, if you’re lucky, that first malicious program doesn’t do anything worse than changing the phone’s wallpaper (Worm:iOS/Ikee.A is a good example here). So, for the user, the cost for the malware creator’s bragging rights is: time spent dealing with the problem and probably a massive headache.

Not a good loss, but bearable. Unfortunately, the next two potential losses for a user hit by mobile malware – money and/or personal data – are more serious.

“Give me back my phone!”

As other attackers get hold of that pioneer program and modify it to be more malicious, the next few versions (or variants) of it usually get more ‘risky’ to the user. If the malware is really malicious, it can alter the phone’s functionality to the point that the device is basically ‘bricked’ – it can’t be used for anything other than a paperweight.

Some examples we saw on the Symbian platform – which, by virtue of being the first widely used smartphone platform, also suffered the most threats – were Cardtrap, Skulls, Romride and Locknut. At this point, if the damage isn’t recoverable, the user is also out by the price of the phone and loss of the data stored on the phone itself. Ouch.

SMSes = $$$

Still, not everyone has to be concerned about data loss, if they have their contacts backed up elsewhere and they don’t keep financial or confidential details on their phone. What if you do, though? Say, you do mobile bank transactions, or store your PINs or account log-in details on the phone? Can an attacker find a way to pull confidential data off the phone?

‘Early generation’ smartphones – for the sake of this article, let’s say they’re the ones that sent data out by WAP  – didn’t give crooks a lot of options for getting hold of data they could make money from.  On these phones, the ‘traditional’ way for crooks to make money was through what amounts to SMS fraud (an example is the Redoc trojan family).

In this kind of scheme, the attackers has to plant a trojan on the device that forces it to send SMS messages to a premium phone number, which can wrack up a high phone bill for the user. Though effective, these attacks tend not to be very widespread, as they are limited by the geographical location and size of the telecom networks and target-able users. If you’re not in the target group, the threat is almost nonexistent.

Stealing data

Nowadays though, ‘new generation’ smartphones – as in ones with fast data connections back up by unlimited or cheap data packages from telco providers, making it convenient for a user to just leave the data connection open – offer a crook more options. Instead of bothering with SMS fraud, they can create malware that find and retrieve specific information stored on the device, which could potentially give far greater returns. Case in point is the very next Ikee variant, Ikee.B, which stole financially-sensitive information stored on the phone.

In this case, the loss is hard to estimate as fortunately, this type of malware isn’t common and the risk they pose is highly individual, depending on what details you store on your phone. It would probably also depend on how the attacker would be able to convert the details stolen into hard cash – sell it off in bulk together with details stolen from others? Find a way to log into a compromised account and withdraw the money?

There’s no ‘standard scenario’ here, so it’s hard for a user to realistically evaluate the fallout of having data stolen off their phone. All that can be reliably said is that personal and financial details are major targets on a PC and they’re probably no less attractive on mobile devices; it’s just that up until now, attackers didn’t have a way to scam these details out of someone on a mobile device.

Going straight for the money

As with PC threats, the main motivation for mobile threats seems to have transitioned from bragging rights to making money. And in a totally unscientific personal observation, it sure seems like mobile malware made that transition much faster than PC threats did. As a very rough comparison:

  • Brain, the first PC-based malware, came out in 1986; it was only in the early 2000’s that profit-motivated malwares became prevalent (though there doesn’t seem to be any agreement on which was the first).
  • By comparison, the iOS was launched in early 2007; its first trojan (of the bragging rights variety) came out almost exactly a year later; and shortly thereafter came Ikee.B, which was more malicious (but only on jailbroken iPhones).
  • The Android OS was launched in late 2007; its first trojan was also the first to try an SMS fraud scam, and it appeared in August of 2010.

It’s early days yet for mobile threats so we really don’t know how they are going to evolve.

It would probably be a safe bet to say that there are going to be more new threats though, and not all of them are going to be as benign as a plastering on a Rick Astley wallpaper.

Next week, the last in this series – How (can I protect myself)?

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