Today we will learn How to hack android devices using the stagefright vulnerability.
In July 2015, mobile security firm Zimperium announced that it had discovered a very serious vulnerability in the Android operating system. The critical bug exists in a core component called “StageFright”, which is the native media playback library that Android uses to record, process, and play media files.
More details were revealed at the BlackHat conference in August 2015 – but not before reports revealed that billions of Android devices could potentially be compromised without users knowing. The researchers said that StageFright’s vulnerabilities are all “remote execution” bugs that allow malicious hackers to infiltrate Android devices and exfiltrate personal data.
How does stagefright work?[How to hack android devices using the stagefright vulnerability]
StageFright can use videos sent via MMS as a source of attack through the libStageFright mechanism that helps Android process video files. Several text messaging apps – including Google Hangouts – automatically process videos, so the infected video is ready for users to watch as soon as they open the message. Because of this, an attack could occur without users even knowing.
It seems laborious, but it works in seconds: a typical StageFright attack penetrates a device in 20 seconds. And while it’s most effective on stock Android devices like the Nexus 5, it’s been known to work on customized Android variants running on phones like the Samsung Galaxy S5, LG G3, and HTC One. StageFright’s popularity has made it the first mobile-only threat to appear in the WatchGuard Threat Lab’s list of the top ten hacks detected by IPS in 2017.
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How to use stagefright to hack android
The StageFright component is implemented in native code (i.e. C++), instead of memory-safe languages such as Java, because media processing is time-sensitive. This alone can result in memory corruption. Therefore, researchers analyzed the deepest recesses of this code and discovered several vulnerabilities that attackers can exploit using various hacking techniques, including methods that do not even require a user’s mobile number.
Here are three of StageFright’s most popular hacking techniques.
1. Place exploit in android app
In the original hacking method (discussed later), the hacker had to know the user’s cell phone number in order to run StageFright via MMS. If the adversary wants to attack a large number of Android phones with this message, he should first collect a large number of phone numbers and then spend money sending text messages to potential victims.
2. Embed exploit in HTML webpage
The adversary simply embeds the infected MP4 file into an HTML web page and publishes the web page on the Internet. Once a visitor opens the page from their Android device, a malicious multimedia file is downloaded, resetting the device’s internal state. The attacker’s server then transmits a self-generated video file to the victim’s device, exploiting the StageFright vulnerability to reveal additional details about the device’s internal state. Using the details sent by the exploit to the hacker’s server, the hacker is able to control the victim’s smartphone.
3. Using multimedia message (MMS) for exploit
With this method, the adversary only requires your phone number. They will then send you an MMS with an infected MP4 file. When the file is downloaded, the hacker remotely executes malicious code on your Android device, which can lead to compromise of your private information or data loss.
And since users get a preview of any message received over the air on all the latest versions of the Android operating system, it means that the attached malicious file will be downloaded automatically. Additionally, apps like Hangouts have an autoload feature. This increases the severity of the threat as it does not require users to take any action to be exploited.
Basically, an adversary can just send a message, run the code, and erase the trace while the victim is asleep (the message can be deleted before the user even sees it). The next day, the user continues to use their affected phone, unaware of the compromise.
How can I protect my android device from stagefright attacks?
Google fixed the bug in the latest version of the Android operating system. However, a large number of Android users have an older version of Android, so it’s up to their device manufacturers to protect their devices from StageFright.
Since manufacturers sometimes take a long time to release patches, here is a list of things users can do to reduce their exposure to the StageFright vulnerability.
Disable automatic download of mms: Users can find this option in message settings. When disabled, MP4 files will not download automatically – they will require the user to tap a placeholder or similar element. So there is no risk if the user does not choose to download the MMS.
Installing apps from the official Play Store: Instead of downloading apps through third-party websites, users should look for their official Play Store versions. It is also a good idea to read the reviews of the app before proceeding with the installation.
Be vigilant when visiting websites: Do not click or open suspicious links on the Internet. Click-bait titles may tempt you to download attachments, but it’s always wise to do a self-diagnosis of the site before taking action. Does it look legit? Does a similar site also require attachment downloads? Answers to questions like these will allow you to make an informed decision.