How to remove Wroba (Xloader/MaqHao) backdoor malware from your Android device
Written by Tomas Meskauskas on (updated)
What is Wroba malware?
Wroba (also known as XLoader or MaqHao) is a backdoor-type malicious program, which our researchers have sampled from VirusTotal. This Android OS-targeting malware has been observed being proliferated via the "Roaming Mantis" SMiShing campaign. Initial operations centered Asia - Japan, Taiwan, Korea, China, and India. However, "Roaming Mantis" has begun targeting Europe as well, with France and Germany being areas of particular interest.
Wroba malware overview
Based on our research and analysis, Wroba is designed to infiltrate Android devices - execute malicious commands and steal data from infected systems. This malware begins its operations by gathering information about the mobile device.
Wroba is capable of modifying Wi-Fi settings, force-opening websites, locking the phone, displaying the home screen, and executing other commands. This backdoor can also send SMSes (text messages), which could be used to further the malware via SMiShing or to text premium numbers (generate revenue through SMS fees).
New versions of Wroba can obtain gallery folders and photos stored in the compromised device. Cyber criminals often use such features in the hopes of acquiring personally identifiable or finance-related data (e.g., ID card or driver's license photos, monetary transaction screenshots, etc.). Furthermore, compromising content could be used for blackmail or sextortion purposes.
To summarize, Wroba backdoor malware infections can result in severe privacy issues, financial losses, and even identity theft.
| Name | Wroba (Xloader/MaqHao) virus |
| Threat Type | Android malware, malicious application. |
| Detection Names | Avast-Mobile (Android:Evo-gen [Trj]), ESET-NOD32 (Multiple Detections), Fortinet (Android/Agent.IFT!tr), Kaspersky (HEUR:Trojan-Dropper.AndroidOS.Wroba.o), McAfee (Artemis!527B5EEBB6DB), Full List (VirusTotal) |
| Symptoms | The device is running slow, system settings are modified without user's permission, questionable applications appear, data and battery usage is increased significantly, browsers redirect to questionable websites, intrusive advertisements are delivered. |
| Distribution methods | Infected email attachments, malicious online advertisements, social engineering, deceptive applications, scam websites. |
| Damage | Stolen personal information (private messages, logins/passwords, etc.), decreased device performance, battery is drained quickly, decreased Internet speed, huge data losses, monetary losses, stolen identity (malicious apps might abuse communication apps). |
| Malware Removal (Android) | To eliminate possible malware infections, scan your mobile device with legitimate antivirus software. Our security researchers recommend using Combo Cleaner. |
Android-specific malware examples
SharkBot, Medusa, FaceStealer, and PixStealer are just a few examples of Android-targeting malware. Generally, malicious software can have a wide variety of harmful abilities, which can be in various combinations.
Popular functionalities include: file/data extraction, additional malware download/installation, remote access/control enablement, spying (e.g., keylogging, recording audio/video via microphones and cameras, etc.), data encryption/ screen-locking for ransom purposes (ransomware), and so on.
Regardless of how malware operates, its infections endanger device integrity and user safety. Therefore, we strongly advise eliminating all threats immediately upon detection.
How did Wroba infiltrate my device?
As mentioned in the introduction, Wroba has been actively spread via a SMiShing campaign named "Roaming Mantis". This technique entails sending text messages that include links to malicious websites, which either stealthily download/install malware or trick users into doing so themselves.
In the "Roaming Mantis" campaigns, Android users are redirected to malware-proliferating sites, while iOS devices open phishing webpages. Furthermore, if the user's IP address (geolocation) is not included in the target list, they are presented with a fake "error 404" (website not found) page.
It is possible for Wroba to infiltrate devices via different methods, as cyber criminals often employ multiple techniques to distribute malware.
In addition to SMiShing, email spam campaigns are used. Spam emails can contain infectious files as attachments or download links. Virulent files can be archives, executables, PDF and Microsoft Office documents, JavaScript, etc. When the files are opened - the infection chain is triggered.
Malicious software can also be disguised as or bundled with ordinary content and distributed via dubious download channels (e.g., unofficial and freeware websites, Peer-to-Peer sharing networks, etc.). Illegal activation tools ("cracks") can infect systems instead of activating licensed programs. Fake updaters cause infections by exploiting outdated software weaknesses and/or by installing malware.
How to avoid installation of malware?
We highly recommend exercising caution with incoming mail (e.g., emails, SMSes, etc.). Therefore, the links and attachments present in suspicious messages must not be opened, as that can result in a system infection. Additionally, we advise researching software and only downloading from official/verified sources. Furthermore, all programs must be activated and updated with tools provided by legitimate developers.
We must emphasize the importance of having a reputable anti-virus installed and kept up-to-date. This software must be used to run regular system scans and to remove detected threats.
Update 20 January 2022: Recently, Wroba malware has been updated to a newer version. The updated version includes a DNS changer that detects vulnerable WiFi routers and modifies their DNS settings. Wroba changes DNS settings to spread the infection to other devices.
Devices connected to vulnerable WiFi networks are redirected to phishing websites or pages hosting malware. The newest Wroba version is distributed using SMS phishing (text messages containing links to malicious pages).
Update 5 April 2023: Now Wroba has a new feature enabling the malware to bypass CAPTCHA security access mechanisms in wireless routers. It can bypass text-based CAPTCHAs. This feature is used in combination with brute-force attacks on wireless router’s web interfaces to compromise routers and perform DNS hijacking attacks.
Update February 12, 2024 – While SMiShing campaigns continue to be the primary methods utilized to proliferate Wroba malware, new developments have been noted in its infection chain. The latest iterations of Wroba can self-execute on devices.
The previous chains followed this model: reception of spam SMS, the malicious link being clicked, download of the infectious file, installation, launching, and granting permissions. However, the newest variants skip the launch part.
Another development of note is the use of Unicode strings to mask the malware's APKs as genuine software. The Google Chrome browser has been used as a disguise. Hence, when victims are presented with a request to grant permission for default SMS software – it appears as though Chrome is asking. This request has been observed in English, French, German, Hindi, Japanese, and Korean.
At the time of writing, Android devices with enabled Google Play Protect (on by default) are safe from this type of malware.
Quick menu:
- Introduction
- How to delete browsing history from the Chrome web browser?
- How to disable browser notifications in the Chrome web browser?
- How to reset the Chrome web browser?
- How to delete browsing history from the Firefox web browser?
- How to disable browser notifications in the Firefox web browser?
- How to reset the Firefox web browser?
- How to uninstall potentially unwanted and/or malicious applications?
- How to boot the Android device in "Safe Mode"?
- How to check the battery usage of various applications?
- How to check the data usage of various applications?
- How to install the latest software updates?
- How to reset the system to its default state?
- How to disable applications that have administrator privileges?
Delete browsing history from the Chrome web browser:
Tap the "Menu" button (three dots on the right-upper corner of the screen) and select "History" in the opened dropdown menu.
Tap "Clear browsing data", select "ADVANCED" tab, choose the time range and data types you want to delete and tap "Clear data".
Disable browser notifications in the Chrome web browser:
Tap the "Menu" button (three dots on the right-upper corner of the screen) and select "Settings" in the opened dropdown menu.
Scroll down until you see "Site settings" option and tap it. Scroll down until you see "Notifications" option and tap it.
Find the websites that deliver browser notifications, tap on them and click "Clear & reset". This will remove permissions granted for these websites to deliver notifications. However, once you visit the same site again, it may ask for a permission again. You can choose whether to give these permissions or not (if you choose to decline the website will go to "Blocked" section and will no longer ask you for the permission).
Reset the Chrome web browser:
Go to "Settings", scroll down until you see "Apps" and tap it.
Scroll down until you find "Chrome" application, select it and tap "Storage" option.
Tap "MANAGE STORAGE", then "CLEAR ALL DATA" and confirm the action by taping "OK". Note that resetting the browser will eliminate all data stored within. This means that all saved logins/passwords, browsing history, non-default settings and other data will be deleted. You will also have to re-login into all websites as well.
Delete browsing history from the Firefox web browser:
Tap the "Menu" button (three dots on the right-upper corner of the screen) and select "History" in the opened dropdown menu.
Scroll down until you see "Clear private data" and tap it. Select data types you want to remove and tap "CLEAR DATA".
Disable browser notifications in the Firefox web browser:
Visit the website that is delivering browser notifications, tap the icon displayed on the left of URL bar (the icon will not necessarily be a "Lock") and select "Edit Site Settings".
In the opened pop-up opt-in the "Notifications" option and tap "CLEAR".
Reset the Firefox web browser:
Go to "Settings", scroll down until you see "Apps" and tap it.
Scroll down until you find "Firefox" application, select it and tap "Storage" option.
Tap "CLEAR DATA" and confirm the action by taping "DELETE". Note that resetting the browser will eliminate all data stored within. This means that all saved logins/passwords, browsing history, non-default settings and other data will be deleted. You will also have to re-login into all websites as well.
Uninstall potentially unwanted and/or malicious applications:
Go to "Settings", scroll down until you see "Apps" and tap it.
Scroll down until you see a potentially unwanted and/or malicious application, select it and tap "Uninstall". If, for some reason, you are unable to remove the selected app (e.g., you are prompted with an error message), you should try using the "Safe Mode".
Boot the Android device in "Safe Mode":
The "Safe Mode" in Android operating system temporarily disables all third-party applications from running. Using this mode is a good way to diagnose and solve various issues (e.g., remove malicious applications that prevent users you from doing so when the device is running "normally").
Push the "Power" button and hold it until you see the "Power off" screen. Tap the "Power off" icon and hold it. After a few seconds the "Safe Mode" option will appear and you'll be able run it by restarting the device.
Check the battery usage of various applications:
Go to "Settings", scroll down until you see "Device maintenance" and tap it.
Tap "Battery" and check the usage of each application. Legitimate/genuine applications are designed to use as low energy as possible in order to provide the best user experience and to save power. Therefore, high battery usage may indicate that the application is malicious.
Check the data usage of various applications:
Go to "Settings", scroll down until you see "Connections" and tap it.
Scroll down until you see "Data usage" and select this option. As with battery, legitimate/genuine applications are designed to minimize data usage as much as possible. This means that huge data usage may indicate presence of malicious application. Note that some malicious applications might be designed to operate when the device is connected to wireless network only. For this reason, you should check both Mobile and Wi-Fi data usage.
If you find an application that uses a lot of data even though you never use it, then we strongly advise you to uninstall it as soon as possible.
Install the latest software updates:
Keeping the software up-to-date is a good practice when it comes to device safety. The device manufacturers are continually releasing various security patches and Android updates in order to fix errors and bugs that can be abused by cyber criminals. An outdated system is way more vulnerable, which is why you should always be sure that your device's software is up-to-date.
Go to "Settings", scroll down until you see "Software update" and tap it.
Tap "Download updates manually" and check if there are any updates available. If so, install them immediately. We also recommend to enable the "Download updates automatically" option - it will enable the system to notify you once an update is released and/or install it automatically.
Reset the system to its default state:
Performing a "Factory Reset" is a good way to remove all unwanted applications, restore system's settings to default and clean the device in general. However, you must keep in mind that all data within the device will be deleted, including photos, video/audio files, phone numbers (stored within the device, not the SIM card), SMS messages, and so forth. In other words, the device will be restored to its primal state.
You can also restore the basic system settings and/or simply network settings as well.
Go to "Settings", scroll down until you see "About phone" and tap it.
Scroll down until you see "Reset" and tap it. Now choose the action you want to perform:
"Reset settings" - restore all system settings to default;
"Reset network settings" - restore all network-related settings to default;
"Factory data reset" - reset the entire system and completely delete all stored data;
Disable applications that have administrator privileges:
If a malicious application gets administrator-level privileges it can seriously damage the system. To keep the device as safe as possible you should always check what apps have such privileges and disable the ones that shouldn't.
Go to "Settings", scroll down until you see "Lock screen and security" and tap it.
Scroll down until you see "Other security settings", tap it and then tap "Device admin apps".
Identify applications that should not have administrator privileges, tap them and then tap "DEACTIVATE".
Frequently Asked Questions (FAQ)
My Android device is infected with Wroba malware, should I format my storage device to get rid of it?
No, formatting is unnecessary for Wroba's removal.
What are the biggest issues that Wroba malware can cause?
The threats a piece of malicious software poses - depend on its functionalities and the cyber criminals' aims. In general, malware infections can lead to severe privacy issues, permanent data loss, financial losses, and identity theft.
What is the purpose of Wroba malware?
Most malware infections are designed to generate revenue for the developers. However, other reasons for these attacks include - cyber criminals' amusement, process disruption (e.g., websites, services, companies, organizations, etc.), personal grudges, political/geopolitical motivations, and so on.
How did Wroba malware infiltrate my computer?
Malware is primarily spread through spam mail, drive-by (stealthy and deceptive) downloads, freeware and third-party download websites, Peer-to-Peer sharing networks, online scams, illegal software tools ("cracks"), fake updates, and so on. Some malicious programs can self-proliferate via local networks or removable storage devices (e.g., external hard drives, USB flash drives, etc.).
Will Combo Cleaner protect me from malware?
Yes, Combo Cleaner can detect and eliminate most of the known malware infections. It is noteworthy that high-end malicious software tends to hide deep within systems - therefore, performing a complete system scan is essential.
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