A new Android miner malware has been uncovered – ADB.Miner. The miner is wormable and is designed to scan a wide range of IP addresses to locate vulnerable devices. The miner was discovered by researchers at Netlab security firm.
ADB.Miner – A Closer Look
Apparently, the miner is the first worm for Android that reuses the scanning code used in the infamous IoT Mirai botnet. The researchers were able to capture 9 samples of the malware, concluding that their core functions are worm propagation and mining:
– Worm infection: Infected device will initiate port scan on TCP 5555 adb interface, and attempt to – execute ADB command to copy itself to newly infected machines.
– XMR Mining: It will dig XMR tokens after infection.
More specifically, the worm uses code from Mirai’s syn scanning module which adds more efficiency to the malware as a whole. What is interesting is that the worm doesn’t employ a command and control server and directly obtains the cryptocurrency income via a single wallet address, researchers say.
ADB.Miner is designed to scan for various types of Android devices ranging from smartphones and smart TVs to TV set-top boxes. The only specification is that these devices should be with publicly accessible ADB debug interface using port 5555 to run. Once located, the worm infects them with the mining module of the malware which seeks to mine Monero cryptocurrency.
The worm’s propagation is implemented through a feature known as droidbot. Once the worm discovers devices with port 5555 adb enabled, it will implant all the samples from local to the victim, using specific commands like the adb connect/adb push/adb shell.
As already mentioned, ADB.Miner uses the scan module source code from Mirai:
– Mirai SYN Scan module is found inside this module to accelerate the port 5555 scan. The following figure highlights the code that constructs a random IP with a target port 5555.
– The code structure is also similar to Mirai.
– This module also contains Mirai string tables, which are weak passwords encrypted by Mirai’s default key 0xdeadbeef. However, these weak passwords are NOT used in this worm.
In addition, ADB.Miner not only seeks to mine Monero but also propagate itself by scanning for more vulnerable devices on the Internet. Unfortunately, the type of vulnerability used in this operation is not known yet. What researchers believe is that the attackers are not leveraging one single flaw to target a specific vendor. As a matter of fact, researchers found devices from a number of manufacturers that were prone to this attack.
So far, the researchers detected 7,400 unique IP addresses which use the Monero mining code. Most victims are located in China and South Korea.
To avoid infection, Android users should implement a security solution on their devices and be extra vigilant with what apps they download, even from Play Store.