Android SharkBot Droppers on Google Play Underline Platform's Security Needs

Android SharkBot Droppers on Google Play Underline Platform's Security Needs

A common theme we've noticed in the last few months consists of malicious apps distributed directly from the Google Play Store. If something comes from an official store, people could be inclined to believe it’s safe. Our research has shown this to be false, many times over.

Only a few months ago, Bitdefender found a trove of malicious apps in the official store that pushed aggressive unwanted ads that could lead to more serious attacks.

Thanks to our real-time behavioral technology designed to detect software acting suspiciously, we uncovered apps downloaded from Google Play acting as droppers for SharkBot bankers shortly after installation, depending on the user's location.

The Google Play Store would likely detect a trojan banker uploaded to their repository, so criminals resort to more covert methods. One way is with an app, sometimes legitimate with some of the advertised features, that doubles as a dropper for more insidious malware.

The apps Bitdefender found are disguised as file managers, which explains why they request permission to install external packages (REQUEST_INSTALL_PACKAGES) from the user. Of course, that permission is used to download malware. As Google Play apps only need the functionality of a file manager to install another app and the malicious behavior is activated to a restricted pool of users, they are challenging to detect.

While none of the apps in this research are still available on the Google Play Store, they're still present across the web in different third-party stores, making them a current threat.

Most users who have downloaded the apps are primarily from the United Kingdom and Italy, with a small minority in other countries as well.

X-File Manager

We found the application X-File Manager (com.victorsoftice.llc) from Google Play that had more than 10,000 installs before it was deleted.

The application installs a SharkBot sample with the label _File Manager, and the user is tricked into thinking that an update to the app must be installed.

The developer profile on Google Play seems to be visible only to users from Italy and Great Britain. Accessing its page without specifying the country code is not possible.

Multiple users claim that the application drops malware, and the target of the criminals becomes apparent as the negative reviews for the apps are all in Italian.

When we took a closer look at the X-File Manager app we found the sample has multiple permissions expected of a file manager, including READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE, GET_ACCOUNTS, REQUEST_INSTALL_PACKAGES, QUERY_ALL_PACKAGES, REQUEST_DELETE_PACKAGES.

Upon code analysis, we discovered the application performs anti-emulator checks and targets users from Great Britain and Italy by verifying if the SIM ISO corresponds with IT or GB. It also checks if the users have installed at least one of the targeted banking applications on their devices.

Searching for the targeted bank:

The encryption of the country codes, URL, banking list was also found in this sample:

Here’s a list of apps monitored by the malware that includes other financial services. It’s worth noting that this is not a fixed list as the attackers can always add support for new apps.

Package name

Financial institution

com.barclays.android.barclaysmobilebanking

Barclays

com.bankofireland.mobilebanking

Bank of Ireland Mobile Banking

com.cooperativebank.bank

The Co-operative Bank

ftb.ibank.android

AIB (NI) Mobile

com.nearform.ptsb

permanent tsb

uk.co.mbna.cardservices.android

MBNA Mobile App

com.danskebank.mobilebank3.uk

Mobile Bank UK – Danske Bank

com.barclays.bca

Barclaycard

com.tescobank.mobile

Tesco Bank and Clubcard Pay+

com.virginmoney.uk.mobile.android

Virgin Money Mobile Banking

com.cooperativebank.smile

 "smile - the internet bank"

com.starlingbank.android

Starling Bank - Mobile Banking

uk.co.metrobankonline.mobile.android.production

Metro Bank

uk.co.santander.santanderUK

Santander Mobile Banking

uk.co.hsbc.hsbcukmobilebanking

HSBC UK Mobile Banking

uk.co.tsb.newmobilebank

TSB Mobile Banking

com.grppl.android.shell.BOS

Bank of Scotland Mobile App

com.grppl.android.shell.halifax

Halifax Mobile Banking

com.grppl.android.shell.CMBlloydsTSB73

Lloyds Bank Mobile Banking

it.copergmps.rt.pf.android.sp.bmps

Banca MPS

it.extrabanca.mobile

NewExtraMobileBank

it.relaxbanking

RelaxBanking Mobile

it.bnl.apps.banking

BNL

it.bnl.apps.enterprise.hellobank

Hello Bank!

it.ingdirect.app

ING Italia

it.popso.SCRIGNOapp

SCRIGNOapp

posteitaliane.posteapp.appbpol

BancoPosta

com.latuabancaperandroid

Intesa Sanpaolo Mobile

com.latuabancaperandroid.pg

 Intesa Sanpaolo Business

com.latuabancaperandroid.ispb

Intesa Sanpaolo Private

com.fineco.it

Fineco

com.CredemMobile

Credem

com.bmo.mobile

BMO Mobile Banking

com.fideuram.alfabetobanking

Alfabeto Banking

com.lynxspa.bancopopolare

YouApp - Mobile Banking

com.vipera.chebanca

CheBanca!

The URL redirects to a Russian Federation IP:

  • http://94[.]198[.]53[.]205/loader_08_2022_03e19619736ebb206d5dc24b6ca3a84f/

The application performs a request at URI, downloads the package, and writes the malicious payload on the device. The dropper fakes an update of the current application to complete the installation and asks the user to install the dropped APK.

While the app is no longer available on the Google Play Store, it’s still on other websites:

Other similar sample found on Google Play

FileVoyager is also a file manager following the same pattern.

Users also claim that the application is suspicious and even malware.

The same encrypted list containing country codes, URL, and banks can be found in com.victorsoftice.llc.

We also found a similar sample named 'Phone AID, Cleaner, Booster' available on the web through third-party app stores:

'LiteCleaner M' is yet another Sharkbot sample that was published on Google Play then deleted, but not before being downloaded by over 1,000 people. It is still present on various third-party online websites.

SharkBot Droppers packages and Indicators of Compromise:

Package name

com.victorsoftice.llc

com.potsepko9.FileManagerApp

com.sidalistudio.developer.app

com.ltdevelopergroups.litecleaner.m

IOCs:

fa7947933a3561b7174f1d94472dcf8633a03749c14342ce65dafe94db361140

5481908f7cf651fde7b902f70c5c6f900a413de5976e1e0ba2b60c44f2a060c4

5ee5894c2be17c542601c113225862129ed96da6e6bd0d80c5ef0d500ad21fe3

0fb6f45af7834c742db0c7b68a61d177c49bb4c59e19640c62723c6b38a777ad

6f1eb9c21b026eecfd65459ec4cffe3954d24619010741e18722108d7bacf3d1

5e858fa31abe3b048be815a96234daa1123a9aab113d6f80b95dbf9437fb7343

e2d2e7683e07c5ffa7b5475433057cec5c2993167f47ea650941f9871923792d

72512e7de8099e66beb9b4395b8c4a5c1dfd413c85977a31480ff8bd68b2ca6e

218c6e2327c8342192dc58c6e793fc3d5cba7f15e4b2f188c98cd4ba48bf244a

844efceeeeff73da35ac13c217ad5723c456ecec01fada7f92b9203fc29e7dcd

25e2a148a586acc6b741a64f42c618796a08ec9745eb3d1170acabf9e732a366

900fe34d5394689c86ead76666e79620ad7a10109c75d661af9bc7d8fb0c27b8

b45edcbdfe9ad1a1990d723dca4405014a4fa1c578b75799219a4298b16175de

618ee1e79a927c57831527faf19739276f2706b6200ee8f52aa0eb0c66de6828

The SharkBot sample is detected as Android.Trojan.Banker.ZP

9a8345bcbc06fc4225d7b03d0a8a4c04c3e7b2fafbf9e00e7ca57dd95034ae34

tags


Author


Elena FLONDOR

When I am not looking at malware I usually enjoy reading a good book, spending time with my family, or traveling.

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Albert ENDRE-LASZLO

Junior Security Researcher at Bitdefender, eager to learn anything about computer works. In his free time, he likes to take motorcycle rides and travel.

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Vlad Sebastian CREȚU

I'm a Junior Security Researcher at Bitdefender, usually prefer to pass the time reading, volunteering, playing chess, and coding

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Adina MATEESCU

As part of Bitdefender's android research team, it became natural for her to develop a passion for analyzing malware and developing continuous automated threat elimination tools.

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Alexandra BOCEREG

I'm a Security Researcher at Bitdefender, and when I'm not looking at code, I spend my time enjoying a good book, traveling, and swimming.

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Silviu STAHIE

Silviu is a seasoned writer who followed the technology world for almost two decades, covering topics ranging from software to hardware and everything in between.

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