SpyNote Android Trojan Builder Leaked

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July 28, 2016 at 1:40 PM

Category: Malware, Threat Prevention, Unit 42

This post is also available in: 日本語 (Japanese)

Our team recently discovered a new Android Trojan called SpyNote which facilitates remote spying. The builder, which creates new versions of the malware, recently leaked on several malware discussion forums. SpyNote is similar to OmniRat and DroidJack, which are RATs (remote administration tools) that allow malware owners to gain remote administrative control of an Android device.

Like these other RATs, SpyNote has a large feature set including the following:

No root access required
Install new APKs and update the malware
Copy files from device to computer
View all messages on the device
Listen to calls made on the device
List all the contacts on the device
Listen live or record audio from the device's microphone
Gain control of the camera on the device
Get IMEI number, Wi-Fi MAC address, and cellphone carrier details
Get the device’s last GPS location
Make calls on the device

Figure 1: SpyNote Control Panel

The SpyNote APK requires victims to accept and give SpyNote many permissions, including the ability to edit text messages, read call logs and contacts, or modify or delete the contents of the SD card. We have found that a sample of SpyNote was uploaded to the VirusTotal and Koodous malware analysis websites.

Analysis

Upon installation, SpyNote will remove the application’s icon from the victim’s device. Also apparent is that the SpyNote builder application is developed in .NET

The application is neither obfuscated nor protected with any Obfuscator or Protector.

Figure 2: Decompiled SpyNote Builder

The uploader might be following the instructions described in YouTube videos on using SpyNote, considering the port number used is exactly the same as in the videos (https://www.youtube.com/watch?v=E9OxlTBtdkA) and the uploader only changes the icon of the APK file.

Furthermore, this RAT has been configured to communicate to the command and control (C&C) IP address (141.255.147.193) over TCP port 2222 as shown in the image below.

Figure 3 – Dalvik bytecode view using Cerbero profiler

Figure 4 – SpyNote opening a socket connection

Based on the information we have already found, we now know that the malware is using the hard-coded SERVER_IP and SERVER_PORT values (Figure 4) for this socket connection. We can now create an extractor for the C2 information using Androguard (https://github.com/androguard/androguard) as shown below. The spynote.C2.py script (shown below) parses these values from the APK file and prints them to the command line (Figure 5).

Figure 5 – Extracted C2 information

#!/usr/bin/python
import sys
from sys import argv
from androguard.core.bytecodes import apk
from androguard.core.bytecodes import dvm

#---------------------------------------------------
# _log : Prints out logs for debug purposes
#---------------------------------------------------
def _log(s):
    print(s)

if __name__ == "__main__":
    if (len(sys.argv) < 2):
        _log("[+] Usage: %s [Path_to_apk]" % sys.argv[0])
        sys.exit(0)
    else:
        a = apk.APK(argv[1])
        d = dvm.DalvikVMFormat(a.get_dex())
        for cls in d.get_classes():
            #if 'Ldell/scream/application/MainActivity;'.lower() in cls.get_name().lower():
            if 'dell/scream/application/MainActivity;'.lower() in cls.get_name().lower():
                c2 = ""
                port = ""
                string = None
                for method in cls.get_methods():
                    if method.name == '<init>':
                        for inst in method.get_instructions():
                            if inst.get_name() == 'const-string':
                                string = inst.get_output().split(',')[-1].strip(" '")
                            if inst.get_name() == 'iput-object':
                                if "SERVER_IP" in inst.get_output():
                                    c2 = string
                                if "PORT" in inst.get_output():
                                    port = string
                            if c2 and port:
                                break
                server = ""
                if port:
                    server = "{0}:{1}".format(c2, str(port))
                else:
                    server = c2
                _log('C&C: [ %s ]' % server)

#!/usr/bin/python

import sys

from sys import argv

from androguard.core.bytecodes import apk

from androguard.core.bytecodes import dvm

#---------------------------------------------------

# _log : Prints out logs for debug purposes

#---------------------------------------------------

def _log(s):

print(s)

if __name__ == "__main__":

if (len(sys.argv) < 2):

_log("[+] Usage: %s [Path_to_apk]" % sys.argv[0])

sys.exit(0)

else:

a = apk.APK(argv[1])

d = dvm.DalvikVMFormat(a.get_dex())

for cls in d.get_classes():

#if 'Ldell/scream/application/MainActivity;'.lower() in cls.get_name().lower():

if 'dell/scream/application/MainActivity;'.lower() in cls.get_name().lower():

c2 = ""

port = ""

string = None

for method in cls.get_methods():

if method.name == '<init>':

for inst in method.get_instructions():

if inst.get_name() == 'const-string':

string = inst.get_output().split(',')[-1].strip(" '")

if inst.get_name() == 'iput-object':

if "SERVER_IP" in inst.get_output():

c2 = string

if "PORT" in inst.get_output():

port = string

if c2 and port:

break

server = ""

if port:

server = "{0}:{1}".format(c2, str(port))

else:

server = c2

_log('C&C: [ %s ]' % server)

Conclusion

Installing apps from third-party sources can be very risky -- those sources often lack the governance provided by official sources such as the Google Play Store, which, even with detailed procedures and algorithms to weed out malicious applications, is not impregnable. Side-loading apps from questionable sources exposes users and their mobile devices to a variety of malware and possible data loss.

Thus far we have not observed SpyNote used in active attacks but we suspect cyber criminals will begin using it as the building of SpyNote is freely available. Palo Alto Networks AutoFocus users can identify this RAT using the SpyNote tag.

Indicators

SHA256 of SpyNote Samples
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