Top 10 Android Security Risks
Android's popularity is rising among consumers – and hackers.
Last year, Android became the world's second favorite mobile OS, racing past BlackBerry and Apple. 67 million of the nearly 300 million smartphones sold in 2010 were Android-powered devices like the Samsung Galaxy S, Motorola Droid X, and HTC EVO. New Android 3.0 ("Honeycomb") tablets will spur even more growth this year.
As a result, approximately half of enterprises are working to embrace Android devices. One of IT's biggest challenges: Android's consumer roots mean minimal support for enterprise-class security. Here, we consider today's biggest Android security risks and what can be done to mitigate them.
1. AWOL Androids: The top concern about any mobile device is loss. In a Juniper survey, 58 percent of smartphone and tablet users feared not being able to recover lost content. Apple iPhone users can restore nearly everything from iTunes, but Androids are not managed via desktop sync. Data loss can be avoided in two ways. First, install an auto-backup app (e.g., WaveSecure, MyBackup) to enable quick restoration of all that matters to you. Second, enroll your Android with one of the many available "find me" services to locate and recover lost devices.
2. Flimsy passwords: If your Android falls into the wrong hands, more is needed to prevent thieves from stealing broadband service, ringing up SMS fees, reading your email, or abusing VPN connections. In Juniper's survey, 3 out of 4 users locked their smartphones. This is an excellent first line of defense, but users need to understand Android's limitations.
Researchers report using smudges to guess Android swipe-lock patterns over 90 percent of the time. Instead, Androids should be locked with PINs or passwords (2.2 or later) or third-party lock apps such as Norton Mobile or AppProtector. Users may also want to enroll in a remote lock service (often combined with find) but beware of SMS dependencies. Enterprises should use either Exchange ActiveSync or the Android 2.2 Device Admin to remotely enforce password policies, ensuring that devices are routinely locked and lost passwords can be reset.
3. Naked data: A major business risk posed by Android is lack of hardware data encryption. Fortunately, Android 3.0 ("Honeycomb") adds an API to let manufacturers offer encryption and IT enforce use. Unfortunately, existing Androids cannot yet perform hardware encryption. Until self-encrypting Androids appear, stored data can be protected in two ways. First, those remote lock apps and APIs can request remote wipe as well, resetting the device to factory defaults – but only when reachable, without wiping SD card data. For more rigorous protection, enterprises should scramble sensitive data such as email and contacts using self-encrypted apps (e.g., Good for Enterprise, Exchange Touchdown)
4. SMShing: This phishing variant uses texting to trick smartphone users into visiting fraudulent or malicious links. Hackers are now being drawn to Android's popularity and openness. For example, last summer, unlucky SMS recipients were invited to download Trojan-SMS.AndroidOS.FakePlayer, a free Movie Player. Once installed, FakePlayer started texting premium-rate numbers, without user knowledge, ringing up huge bills. To block potentially-costly texts, users can add SMS controls such as SMSLinkGuard. Enterprises may also consider using a Mobile Device Manager (MDM) that can monitor Android wireless expenses (e.g., SMS, roaming).
5. Unsafe surfing: Think web browsing on your Android is safe? Last fall, M.J. Keith showed that a known WebKit browser vulnerability could be exploited on Android 2.0 or 2.1. Thomas Cannon reported an Android 2.2 browser flaw that could give hackers full SD card access. Recently, Google fixed an Android Market cross-site scripting (XSS) vulnerability that enables arbitrary code execution, found by John Oberheide. Unfortunately, Android users cannot quickly patch around bugs, because OS updates are deployed infrequently by carriers. One work-around: Using an app like BadLink Check or TrendMicro to avoid known-malicious websites.
6. Nosy apps: Speaking of the Android Market, telling friend from foe can be hard. According to the App Genome Project, Android Market apps more than doubled in the past 6 months. A whopping 28 percent of those apps now access device location, while 7.5 percent access stored contacts. Do these apps really need to know that info and what are they doing with it? Android apps must request permissions during installation – users need to seriously review those requests, exercise caution, and avoid apps that seem too nosy. To flag intrusive apps already installed on your Android, check out Lookout Mobile Security's Privacy Advisor or Webroot.
7. Repackaged and fraudulent apps: Some apps aren't what they appear to be. Many repackaged apps found on third-party Android markets are legitimate free apps, repackaged to generate ad revenue. But repackaging is also used to implant Android trojans, such as the Android.Pjapps trojan (included in modified versions of the Steamy Windows app) and the Android.Geinimi trojan (turns infected phones into bots). Most of these can be avoided by installing apps only from the Google Android Market. Don't frequent unregulated third-party markets or manually install Android packages from untrusted sources.
But even apps distributed by the Google Android Market receive no official review. Last year, "09Droid" sold about 40 different mobile banking apps at the Android Market. Unfortunately, none were affiliated with those banks. It is unclear whether 09Droid intended to phish for banking passwords, but when banks complained, those fraudulent apps were pulled from the Market. Be very careful when downloading apps that access sensitive accounts. Check with banks or other institutions to confirm apps are distributed by an authorized developer and beware of look-alikes.
8. Android malware: According to traffic analysis by AdaptiveMobile, Android malware spike 400 percent last year. The total is still miniscule compared to other platforms, but more malware is likely to target Android's rapidly-expanding pool of potential victims. When Coverity assessed the Android kernel, it identified 359 code vulnerabilities, 88 of which posed "high risk" of exploitation. Because Android is an open development platform, hackers have ample opportunity to find and learn how to take advantage of these kinds of flaws.
Fortunately, application sandboxing is built into Android to limit potential damage by malicious apps – unless malware breaks out of that sandbox. That is apparently what DroidDream did last month. Hidden inside about 50 Android Market apps, including Sexy Girls, Advanced File Manager, Task Killer Pro, and Advanced Sound Manager, DroidDream "rooted" infected phones, sending IMEI/IMSI and OS version back to a command-and-control server. The "nature of this exploit" so concerned Google that it remotely removed installed apps from an estimated 50K phones. This "kill switch" was a fail-safe measure of last resort, but users can proactively defend themselves using Android anti-malware apps (e.g., Kaspersky, F-Secure).
9. Fake anti-malware: Alas, the fake anti-virus trend sweeping the PC world has now emerged for Android as well. When Google killed DroidDream, it installed a clean-up app called "Android Market Security Tool 2011." Android.Bgserv soon appeared on a third-party Chinese market, pretending to be Google's tool but carrying an SMS trojan. The lesson: Hackers prey on user emotions like fear – don't assume that security apps are legitimate. Check out sellers and read reviews. Enterprises should go further by testing apps in a lab environment, then using an MDM to suggest or auto-install verified safe apps on employee Androids. For example, Sybase Afaria now provides over-the-air app management for Android.
10. Lack of visibility and control: Ultimately, enterprises must embrace Androids – even employee-purchased Androids – so that IT can regain visibility into and control over business activities on these devices. Unlike iOS, Android does not yet offer native MDM to enable third-party device management. However, Android does provide APIs that MDM agent apps can use to read/write settings (e.g., password complexity), query attributes (e.g., installed apps, GPS location), and invoke remote lock or wipe. A bit of this can also be done via Exchange ActiveSync. Either way, IT can enroll Android devices, track their use, and enforce (at least limited) policies. Configurable settings are limited but rapidly expanding – more so for some manufacturers than others. But putting a management framework in place can help you leverage new Android security capabilities as they emerge.
Note: Many of the apps cited above are actually suites that include multiple security tools – for example, remote find, lock, and wipe plus password and anti-malware. We included many different examples for the sake of diversity; shop around to find Android security suite(s) that best fit your own needs.
Lisa Phifer owns Core Competence, a consulting firm focused on business use of emerging network and security technologies. A 29-year industry veteran, Lisa enjoys helping companies large and small to assess, mitigate, and prevent Internet security threats through sound policies, effective technologies, best practices, and user education.
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