How to eliminate SoumniBot malware from your Android device
Written by Tomas Meskauskas on (updated)
What kind of malware is SoumniBot?
SoumniBot is an Android-specific malware. It utilizes sophisticated anti-analysis and anti-detection techniques. This malicious program is designed to exfiltrate sensitive data from devices, with a particular focus on banking-related information. SoumniBot has been observed being leveraged in attacks targeting clients of Korean online banks.
SoumniBot malware overview
As mentioned in the introduction, SoumniBot employs novel anti-detection and anti-analysis techniques. To provide an overview, this malware relies on obfuscating its Android manifest. SoumniBot's developers had detected avenues for exploitation in the manifest extraction and parsing procedures.
Three methods are implemented to complicate detection/analysis. First is the incorrect validation of the compression method field. While typically, unpackers would consider manifests like that of SoumniBot to be invalid, the Android APK parser recognizes it and permits the malware's installation.
Second is the invalid manifest size. The malicious archived manifest is larger than indicated, which causes an overlay. Although parsers following more rigorous protocols would find the file unreadable, the Android APK parser experiences no issue.
Third are the long namespace names. Excessive namespace names render manifests unreadable, but this error is avoided as the Android OS ignores them entirely. Additionally, the malware hides its icon after installation.
Following successful infiltration, SoumniBot begins by establishing a connection with its C&C (Command and Control) server. The malware starts collecting information of interest, e.g., IP address and geolocation data, list of installed applications, mobile service provider, phone number, contact lists, accounts, ringtone volume levels, etc.
SoumniBot can also add and remove contacts. It is capable of exfiltrating victims' SMSes and MMSes, and it can even send text messages. While the latter functionality was not used for any complex purposes at the time of research, it is pertinent to mention that SoumniBot's developers could upgrade it to function as Toll Fraud malware.
This program can exfiltrate photos and videos stored on compromised devices. It can switch between silent modes and debug modes.
SoumniBot searches for digital certificates from Korean banks. These identifying certificates are issued to bank clients in order to enable them to access online banking services and carry out transactions.
It must be mentioned that malware developers commonly improve upon their creations; hence, potential future versions of SoumniBot could boast additional/different abilities and features.
In summary, the presence of software like SoumniBot on devices may lead to severe privacy issues, significant financial losses, and identity theft.
| Name | SoumniBot virus |
| Threat Type | Android malware, malicious application, banking malware, banking trojan. |
| Detection Names | Avast-Mobile (Android:Evo-gen [Trj]), DrWeb (Android.Spy.5987), ESET-NOD32 (A Variant Of Generik.NIEWRII), Fortinet (Android/Agent.MFQ!tr), Kaspersky (HEUR:Trojan-Banker.AndroidOS.SoumniBot), 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. |
| 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. |
Banking malware examples
GoldPickaxe, Greenbean, and Joker are just a couple of our articles on Android malware that seek banking-related information. Malicious software can have various harmful capabilities that are unlimited by the program's classification. For example, data-stealing functionalities are prevalent in general.
However, regardless of how malware operates – its presence on a device threatens system integrity and user safety. Therefore, it is essential to eliminate all threats immediately upon detection.
How did SoumniBot infiltrate my device?
Generally, malware is proliferated using phishing and social engineering tactics. Malicious software is usually disguised as or bundled with legitimate/ordinary content.
The most widespread malware distribution techniques include: drive-by (stealthy/deceptive) downloads, untrustworthy download channels (e.g., freeware and free file-hosting websites, Peer-to-Peer sharing networks, third-party app stores, etc.), malicious attachments/links in spam (e.g., emails, DMs/PMs, SMSes, social media posts, etc.), malvertising, online scams, illegal software activation tools ("cracks"), and fake updates.
Furthermore, some malicious programs can self-spread through local networks and removable storage devices (e.g., external hard drives, USB flash drives, etc.).
It is worth mentioning that malware can be encountered on legitimate download sources, such as the Google Play Store. While the hosting period can be brief, as upload reviewing/reporting systems ensure the malicious content's removal – cyber criminals may still find it profitable.
How to avoid installation of malware?
We strongly recommend researching software by reading terms and user/expert reviews, checking permissions, verifying developer legitimacy, etc. Additionally, all downloads must be performed from official and trustworthy channels. Programs must be activated and updated using genuine functions/tools, as those obtained from third-parties can contain malware.
Another recommendation is to be careful while browsing since fraudulent and dangerous online content usually appears innocuous. Incoming emails and other messages must be treated with care. Attachments or links present in suspicious/irrelevant mail must not be opened, as they can be infectious.
We must stress the importance of having a dependable anti-virus installed and kept updated. Security software must be used to run regular system scans and to remove threats and issues.
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 SoumniBot malware, should I format my storage device to get rid of it?
Malware removal rarely necessitates such drastic measures.
What are the biggest issues that SoumniBot malware can cause?
The threats linked to an infection depend on the malicious program's capabilities and the cyber criminals' goals. SoumniBot is a data-stealing malware that targets banking information. Infections of this kind are associated with severe privacy issues, financial losses, and identity theft.
What is the purpose of SoumniBot malware?
Malware is primarily used for profit. However, cyber criminals can also use malicious software to amuse themselves, carry out personal vendettas, disrupt processes (e.g., websites, services, etc.), engage in hacktivism, and launch politically/geopolitically motivated attacks.
How did SoumniBot malware infiltrate my Android device?
The most commonly used distribution methods include: drive-by downloads, online scams, spam mail, malvertising, dubious download sources (e.g., freeware and free file-hosting sites, P2P sharing networks, third-party app stores, etc.), illegal software activation ("cracking") tools, and fake updates. Some malicious programs can self-proliferate via local networks and removable storage devices.
Will Combo Cleaner protect me from malware?
Yes, Combo Cleaner can detect and eliminate practically all known malware infections. It must be emphasized that performing a complete system scan is crucial since high-end malicious programs typically hide deep within systems.
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