Ransomware: Cause for Alarm for Android Phone Users 0 1814

  • 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.
Ransomware Android Phone

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.

  1. Lock-screen ransomware
  2. 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.

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Approximately US $150,000 worth of Ethereum-based cryptocurrency stolen 0 1654

Online cryptocurrency website MyEtherWallet.com has confirmed that some visitors could have been temporarily redirected to a phishing site designed to steal users’ credentials and – ultimately – empty their cryptocurrency wallets.

According to reports, whoever was behind the attack may have successfully stolen approximately US $152,000 worth of Ethereum-based cryptocurrency.

However,  MyEtherWallet may not have been at fault, as the website explained in its statement:

“This is not due to a lack of security on the [MyEtherWallet] platform. It is due to hackers finding vulnerabilities in public facing DNS servers.”

British security researcher Kevin Beaumont confirms in a blog post that some of MyEtherWallet’s traffic had been redirected to a server based in Russia after traffic intended for Amazon’s DNS resolvers was pointed to a server hosted in Chicago by Equinix.

For the scheme to succeed, someone pulled off a hijack of a crucial component of the internet known as Border Gateway Protocol (BGP), to reroute traffic intended for Amazon’s Route 53 DNS service to the server in Chicago. As a consequence, for some users, entering myetherwallet.com into their browser did not take them to the genuine site but instead to a server at an IP address chosen by the hackers.

The only obvious clue that a typical user might have spotted was that when they visited the fake MyEtherWallet site they would have seen an error message telling them that the site was using an untrustworthy SSL certificate.

It seems that the attackers made a mistake in not obtaining a valid SSL certificate.

Despite the error with their SSL certificate, the hackers haven’t done badly for themselves – both in this attack and in the past. Fascinatingly, the bogus MyEtherWallet website set up by the criminals was moving stolen cryptocurrency into a wallet which already contained some US $27 million worth of assets. Inevitably that raises questions of its own – have the hackers already made a substantial fortune through other attacks, or might their activities be supported by a nation state?

In a statement Equinix confirmed that a customer’s equipment at its Chicago data center was used in the hackers’ hijacking of Amazon’s Route 53 DNS service:

“The server used in this incident was not an Equinix server but rather customer equipment deployed at one of our Chicago IBX data centers… We generally do not have visibility or control over what our customers – or customers of our customers – do with their equipment.”

Amazon however, do not find the blame to lie on themselves, communicating the following statement:

“Neither AWS nor Amazon Route 53 were hacked or compromised. An upstream Internet Service Provider (ISP) was compromised by a malicious actor who then used that provider to announce a subset of Route 53 IP addresses to other networks with whom this ISP was peered. These peered networks, unaware of this issue, accepted these announcements and incorrectly directed a small percentage of traffic for a single customer’s domain to the malicious copy of that domain.”

Some advice from award winning security blogger, researcher and speaker, Graham Cluley – avoid putting your cryptocurrency wallet online, keep them off your smartphone or computer and perhaps instead invest in a hardware wallet.

Beware: ad slingers thinly disguised as security apps 0 1672

Fake Security App

According to AV-Comparatives, an independent testing organization, there are significant differences in the level of protection provided by mobile security solutions. However, even the least secure of them are still far better than questionable apps that impersonate security applications in order to display ads to users. Thirty-five such applications have recently been discovered in the Google Play official Android app store.

These apps have Google Play statistics showing a minimum of over six million installs, cumulatively. However, not all those were necessarily real installations, it is possilbe that many were bot downloads posting fake reviews to improve the ratings for the app.

All 35 apps have been flagged by ESET and eventually removed from the store.

In addition to annoying their victims with ads, disguising these apps as security software has some serious negative side effects, too. In mimicking basic security functions – in fact, they all act as very primitive security checkers relying on a few trivial hardcoded rules – they often detect legitimate apps as malicious. And last but not least, they create a false sense of security in the victims, which might expose them to real risks from malicious apps that are not detected as such.

ESET’s analysis has shown that among these 35 apps, only a handful stand out for their specific features: one app is not completely free as it offers a paid upgrade; one app has implemented a primitive, easily bypassed, app-locker manager; another app flags other apps from this group as dangerous by default; and finally, one misuses ESET’s branding.

 

Security-mimicking functionality
In order to stay under the radar, all the shady ad-displaying apps mimic actual mobile security solutions. However, their ‘detection mechanisms’ are incomplete and very primitive, which makes them easy to bypass and prone to false positives.

Our research into these questionable apps has shown that their ‘detection mechanisms’ can be divided into four categories. These mechanisms are identical or almost identical across the whole set of apps.

1) Package name whitelist & blacklist
These whitelists features popular apps such as Facebook, Instagram, LinkedIn, Skype and others. The ‘blacklists’ contains far too few items to be considered security functionality at all.

2) Permissions blacklist
All apps (including legitimate ones) are flagged if they require some of the listed permissions that are considered dangerous, such as send and receive SMS, access location data, access the camera, etc.

3) Source whitelist
All apps but those from the official Android store, Google Play, are flagged – even if they are completely benign.

4) Activities blacklist
All apps that contain any of the blacklisted activities: that is, parts of applications. This mainly concerns some ad-displaying activities.

Flagged are all apps that contain any of the blacklisted activities, i.e., packages of application that are used in an application. These packages can handle additional functionalities (mainly some ad-displaying activities).

While there is nothing wrong with the idea of activity blacklisting, the implementation in these questionable apps is rather sloppy. For example, Google Ads is included in the blacklist despite the fact that it is a legitimate service. On top of being legitimate, this service is implemented in all of the shady apps we analyzed.

Additional security “functionality”
Some of the questionable security apps are capable of protecting a user’s apps with a password or a pattern locker. The idea behind this seemingly useful feature is to provide the user with another layer of security in selected apps.

However, due to insecure implementation, this feature also fails to provide true security to the user.

The problem is that relevant information is not stored safely on the device – instead of using encryption, which is common baseline practice in cybersecurity, these apps store the names of locked apps and the passwords to unlock them as plaintext.

This means that the data can be accessed after the device is rooted.

Besides compromising the unencrypted data by rooting the phone, there is another way to bypass the app lock. An attacker with physical access to the device can change the app-locking password without knowing the old one!

Conclusion
Having a security solution installed in an Android phone is definitely a good thing. However, not all apps featuring “security” or “antivirus” in their name do what the name promises. Before installing a security solution, think twice: is it really a tool you can safely rely on?

The 35 pseudo-security apps described in this article are not, say, ransomware or other hardcore malware. The only harm they do is displaying annoying ads, making false-positive detections and giving the victim a false sense of security. However, those millions of unwary users who downloaded them could easily have ended up downloading true malware in some similar disguise.

Instead of shady apps with flashy names and icons and outlandish, unsubstantiated promises, seek a reputable security solution. And which one to choose? An independent test by a well-respected testing organization might help.