Authored by Wenfeng Yu and ZePeng Chen
As smartphones have develop into an integral a part of our every day lives, malicious apps have grown more and more misleading and complex. Lately, we uncovered a seemingly innocent app known as “BMI CalculationVsn” on the Amazon App Retailer, which is secretly stealing the bundle title of put in apps and incoming SMS messages beneath the guise of a easy well being software. McAfee reported the found app to Amazon, which took immediate motion, and the app is not obtainable on Amazon Appstore.
Determine 1. Utility printed on Amazon Appstore
Superficial Performance: Easy BMI Calculation
On the floor, this app seems to be a primary software, offering a single web page the place customers can enter their weight and peak to calculate their BMI. Its interface appears to be like solely in keeping with an ordinary well being software. Nevertheless, behind this harmless look lies a variety of malicious actions.
Determine 2. Utility MainActivity
Malicious Actions: Stealing Non-public Knowledge
Upon additional investigation, we found that this app engages within the following dangerous behaviors:
- Display Recording: The app begins a background service to document the display and when the person clicks the “Calculate” button, the Android system will pop up request display recording permission message and begin display recording. This performance is prone to seize gesture passwords or delicate knowledge from different apps. Within the evaluation of the newest present samples, it was discovered that the developer was not prepared for this perform. The code didn’t add the recorded mp4 file to the C2 server, and originally of the startRecording() methodology, the developer added a code that immediately returns and doesn’t execute comply with code.
Determine 3. Display Recorder Service Code
When the recording begins, the permission request dialog will likely be displayed.
Determine 4. Begin Recording Request.
- Put in App Info: The app scans the system to retrieve a listing of all put in functions. This knowledge could possibly be used to determine goal customers or plan extra superior assaults.
Determine 5. Add Consumer Knowledge
- SMS Messages: It intercepts and collects all SMS messages acquired on the system, doubtlessly to seize one-time password (OTP), verification codes and delicate data. The intercepted textual content messages will likely be added to Firebase (storage bucket: testmlwr-d4dd7.appspot.com).
Malware beneath improvement:
Based on our evaluation of historic samples, this malicious app remains to be beneath improvement and testing stage and has not reached a accomplished state. By looking for associated samples on VirusTotal based mostly on the malware’s bundle title (com.zeeee.recordingappz) revealed its improvement historical past. We will see that this malware was first developed in October 2024 and initially developed as a display recording app, however halfway by the app’s icon was modified to the BMI calculator, and the payload to steal SMS messages was added within the newest model.
Determine 6. The Timeline of Utility Improvement
The tackle of the Firebase Set up API utilized by this app makes use of the character “testmlwr” which signifies that this app remains to be within the testing section.
App Developer Info:
Based on the detailed details about this app product on the Amazon web page, the developer’s title is: “PT. Visionet Knowledge Internasional”. The malware creator tricked customers by abusing the names of an enterprise IT administration service supplier in Indonesia to distribute this malware on Amazon Appstore. This reality means that the malware creator could also be somebody with information of Indonesia.
Determine 7. Developer Info
Tips on how to Defend Your self
To keep away from falling sufferer to such malicious apps, we suggest the next precautions:
- Set up Trusted Antivirus Apps: Use dependable antivirus software program to detect and forestall malicious apps earlier than they will trigger hurt.
- Evaluate Permission Requests: When putting in an app, fastidiously look at the permissions it requests. Deny any permissions that appear unrelated to its marketed performance. For example, a BMI calculator has no reliable purpose to request entry to SMS or display recording.
- Keep Alert: Look ahead to uncommon app conduct, reminiscent of decreased system efficiency, fast battery drain, or a spike in knowledge utilization, which may point out malicious exercise working within the background.
Conclusion
As cybercrime continues to evolve, it’s essential to stay vigilant in defending our digital lives. Apps like “BMI CalculationVsn” function a stark reminder that even the only instruments can harbor hidden threats. By staying alert and adopting strong safety measures, we will safeguard our privateness and knowledge.
IoC
Distribution web site:
- hxxps://www.amazon.com/PT-Visionet-Knowledge-Internasional-CalculationVsn/dp/B0DK1B7ZM5/
C2 servers/Storage buckets:
- hxxps://firebaseinstallations.googleapis.com/v1/initiatives/testmlwr-d4dd7
- hxxps://6708c6e38e86a8d9e42ffe93.mockapi.io/
- testmlwr-d4dd7.appspot.com
Pattern Hash:
- 8477891c4631358c9f3ab57b0e795e1dcf468d94a9c6b6621f8e94a5f91a3b6a
