ESET East Africa
- Lock-screen Ransomware and file-encrypting “crypto-ransomware”, have been causing major financial and data losses for many years, and now it's on the Android platform.
- In Kenya, ransomware offers a unique and differentiated threat. One out of every ten global mobile money transactions occur in Kenya.
- Individuals without any protected handsets could be adversely compromised as the human layer of M-PESA’s networking environment is essentially vulnerable.
What is Ransomware?
Ransomware is a growing problem for users of mobile devices. Lock-screen types and file-encrypting “crypto-ransomware”, both of which have been causing major financial and data losses for many years, have made their way to the Android platform.
ESET has prepared a topical white paper on the growth of this insidious Android malware.
Like other types of Android malware – SMS trojans, for example – ransomware threats have been evolving over the past few years and malware writers have been adopting many of the same techniques that have proven to be effective in regular desktop malware.
Both on Windows and on Android, lock-screens have prompts to scare the victims into paying up after (falsely) accusing them of harvesting illegal content on their devices.
Likewise, as with the infamous Windows Crypto locker ransomware family, crypto-ransomware on Android started using strong cryptography, which meant that affected users had no practical way of regaining the hijacked files.
Notably, everyday data (such as photos and texts) is at an elevated risk as this data is stored on phones rather than PCs.
The Woes of Wangari
A good hypothetical example would be Wangari, who when downloading Instagram on her handset accidentally downloaded a malicious masked application disguised to look like the official Instagram app.
The payload for that application may have been amended to have lock-screen ransomware which denies Wangari access to her phone’s interface, and consequently her M-Pesa account.
How much do you think Wangari would pay the hijackers to access her M-Pesa account?
In Kenya, ransomware offers a unique and differentiated threat. One out of every ten global mobile money transactions occur in Kenya. Essentially, a successful ransomware attack in Kenya could lead to a user being deprived access to their mobile money accounts.
Although the M-PESA system has been deemed robust, individuals without any protected handsets could be adversely compromised as the human layer of M-PESA’s networking environment is essentially vulnerable.
Types of Android Ransomware
According to Robert Lipovsky and Lukas Stefanko from ESET Research, ransomware, as the name suggests, is any type of malware that demands a sum of money from the infected user while promising to “release” a hijacked resource in exchange.
There exist two broad categories of malware that can be termed as ransomware.
- Lock-screen ransomware
- Crypto-ransomware
The difference of these types of ransomware is that: in lock-screen types of ransomware, the hijacked resource is access to the compromised system while in file-encrypting “crypto-ransomware” that hijacked resource is the user’s files.
Since ransomware first reared its ugly head when the Windows Operating System was widely adopted, it was only logical that the malware writers would similarly adopt ransomware to compromise mobile phones as they are ubiquitous in the modern day.
With consumers switching more and more from PCs to mobile, more and more valuable data are being stored on these devices that devices, which leads to the fact that more and more valuable data is being stored on those devices that all of us carry around, Android ransomware is becoming ever more worthwhile for attackers.
How to Keep Safe
1. Avoiding Unofficial App Stores:
Among the most important active measures to take are avoiding unofficial app stores and having a mobile security app installed and kept up to date.
2. Back up your Data:
In the event of a successful ransomware attack, having a back-up for all your important data enables you to retrieve vital information, such as sentimental photos and vital business information. Having a backup turns such an experience into nothing more than a nuisance.
According to ESET Research, there exist several options for removal if one is successfully infected.
3. Invest in Mobile Security:
Mobile Security includes malware protection, which can protect users from ransomware through scanning infected applications and quarantining them prior to infection of the given device.
We obviously recommend ESET Mobile Security, available at https://www.eset.com/afr/
What to do when infected
1. Boot the device into Safe Mode:
For most simple lock-screen ransomware families, booting the device into Safe Mode – so third-party applications (including the malware) will not load – will do the trick and the user can easily uninstall the malicious application.
The steps for booting into Safe Mode can vary on different device models. (Consult your manual, or ask Google – the search engine.) If the application has been granted Device Administrator privileges, these must first be revoked from the settings menu before the app can be uninstalled.
2. Use an MDM solution:
If ransomware with Device Administrator rights has locked the device using Android’s built-in PIN or password screen lock functionality, the situation gets more complicated. It should be possible to reset the lock using Google’s Android Device Manager or an alternate MDM solution.
Rooted Android phones have even more options. A factory reset, which will delete all data on the device, can be used as the last resort in case no MDM solutions are available.
3. Contact your Security Provider’s Technical Support:
If files on the device have been encrypted by crypto-ransomware such as Android/Simplocker, we advise users to contact their security provider’s technical support. Depending on the specific ransomware variant, decrypting the files may or may not be possible.
Conclusion
In the event of a ransomware attack, never pay cybercriminals. In certain cases, ESET researchers have discussed ransomware devoid of the code necessary to decrypt malware upon payment. This essentially means that paying cybercriminals does not mean decryption of your data.
Kenyans need to be made aware of the looming ransomware threat which could significantly impact their access to essential mobile services such as M-Pesa. The largest mobile digital economy has a target on its back. We need to remain vigilant.
