Android Rootnik Malware

Original Issue Date:- July 17, 2019

Virus Type:-Android Malware

Severity:- Medium

Rootnik is an android malware toolkit which distributes itself by injecting malicious code into legitimate apps and, after successfully compromising Android device, it launches a fresh thread to gain root privileges. It also begins the process of promoting other apps while downloading encrypted payloads from a remote server to try to gain root access. If successful, it writes four APK files to the system partition and reboots the device.

These four APK files serve as system apps after rebooting and feature static file names: AndroidSettings.apk (responsible for promoting apps), BluetoothProviders.apk and WifiProviders.apk (both acting as remote control components for installing other applications and downloading code), and VirusSecurityHunter.apk (exclusively intended to harvest private data).

This malicious app is capable of performing the following actions:

Abuse a customized version of “Root Assistant” to exploit Android vulnerabilities including CVE-2012-4221, CVE-2012-6422, CVE-2013-2596, CVE-2013-2597, and CVE-2013-6282.
Rooting Android devices
Install several APK files on the system partition of the compromised machine to maintain persistence after successful gaining root access.
Injecting malicious code into legitimate apps
Subscribing to premium services and sending premium messages
Harvest victims’ private information, including their location, phone MAC address, and device ID.
Steal WiFi information, including passwords and keys as well as SSID and BSSID identifiers.

Permissions

Open network connections
Start once the device has finished booting
Access location information, such as Cell-ID or Wi-Fi
Access external storage devices
Write to external storage devices
Access information about networks
Allow access to low-level system logs
Check the phone's current state

Indicators of Infection:

List of Hashes of Malware Binaries

c1775e5fe89a0c8b1254e4d8a95686c56554b47f13e36d4f5cb551cb340f7021
0d612eb6d3ca2bbbc2aa33493065d8b4c3237f3cb262d48602181887ccea1afb
17a00e9e8a50a4e2ae0a2a5c88be0769a16c3fc90903dd1cf4f5b0b9b0aa1139
f6b7b22bbe572c1ac1d7ac7135e076da87491eb78a37f17654a4aa92d88ded24
cee6584cd2e01fab5f075f94af2a0ce024ed5e4f2d52e3dc39f7655c736a7232
e2bdcfe5796cd377d41f3da3838865ab062ea7af9e1e4424b1e34eb084abec4a
e5e22b357893bc15a50dc35b702dd5fcdfeafc6ffec7daa0d313c724d72ec854

File system Changes: Files written to system partition by Rootnik.

3bab02ec7ab2480c65b824350b387b00fc7fd9359ebca34fb42dda340ccbf5b6
dc76856ff79cfdda7b227635f204ff3341e01ea537022497f5c6a70dc46b0cea
ae4be03204419fd96c4e5085b6e3ddd542f39c53f9c9d0fed4eecaf823a1b26e

Network Communications:

Rootnik may attempt to make connections to following C2 domains

grs.gowdsy[.]com
grs.rogsob[.]com
gt.rogsob[.]com
gt.yepodjr[.]com
qj.hoyebs[.]com
qj.hoyow[.]com
applight[.]mobi
jaxfire[.]mobi
superflashlight[.]mobi
shenmeapp[.]info

Countermeasures:

Do not download and install applications from untrusted sources [offered via unknown websites/ links on unscrupulous messages]. Install applications downloaded from reputed application market only.
Install and maintain updated antivirus solution on android devices. Scan the suspected device with antivirus solutions to detect and clean infections.
Prior to downloading / installing apps on android devices (even from Google Play Store), Always review the app details, number of downloads, user reviews, comments and "ADDITIONAL INFORMATION" section.
Verify app permissions and grant only those permissions which have relevant context for the app's purpose.
In settings, do not enable installation of apps from "Untrusted Sources".
Exercise caution while visiting trusted/untrusted sites for clicking links.
Install Android updates and patches as and when available from Android device vendors.
Users are advised to use device encryption or encrypting external SD card feature available with most of the android OS.
Do not download or open attachment in emails received from untrusted sources or unexpectedly received from trusted users.
Avoid using unsecured, unknown Wi-Fi networks. There may be rogue Wi-Fi access points at public places used for distributing malicious applications.
Confirm that the banking app you’re using is the official, verified version.
If anything looks awry or suddenly unfamiliar, check in with your bank’s customer service team.
Use two-factor authentication if it’s available.
Make sure you have a strong AI-powered mobile antivirus installed to detect and block this kind of tricky malware if it ever makes its way onto your system.
Refer to security best practices for mobile Phone users:
http://www.cyberswachhtakendra.gov.in/documents/Mobile_phone_Security.pdf

References: