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Brief Overview of Smishing Apps Targeting TMON and WEMAKEPRICE
2024.08.09

✅ Report Title:


Brief Overview of Smishing Apps Targeting TMON and WEMAKEPRICE



✅ Report Summary:


- Recently, smishing cases exploiting the delayed refund incidents of TMON and WEMAKEPRICE have been identified, with the malicious app collected and analyzed.

- This malicious app not only exfiltrates device information, contacts, message history, and images but also uniquely targets National Public Key Infrastructure (NPKI) certificate information.



📌 What are the detailed analysis findings of the malicious app?


- The malicious app was discovered leveraging recent social issues, such as delayed refunds from TMON and WEMAKEPRICE. It was collected and subjected to preliminary analysis.


- Upon accessing the app distribution source, an app impersonating the Korea Consumer Agency was found, with a downloaded app displaying a police icon.


- When installed and launched, the app requests battery optimization exclusion to maintain persistence and seeks permissions critical for its malicious actions:

    - READ_PHONE_STATE**: Check phone state

    - READ_CONTACTS, WRITE_CONTACTS**: Read and write contact information

    - READ_SMS, SEND_SMS**: Read and send messages

    - READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE**: Read and write storage


- The app then transmits device information, contacts, message history, and images to a Command and Control (C2) server. The domains used by this malicious app include:

    - hxxps://pindirect.mca[.]lol

    - hxxps://skt.mca[.]lol

    - hxxps://tplus.mca[.]lol

    - hxxps://lg.mca[.]lol

    - hxxps://kt.mca[.]lol


- If an "NPKI/yessign" path exists on the infected device, the app compresses the entire NPKI directory, saving it as /storage/emulated/0/NPKI.zip, and sends the file to the C2 server.


- Additionally, when specific values are received in the inst field via the MQTT protocol from the C2 server, the app performs designated malicious actions as follows:

    - 1: Upload contact information (name and phone number)

    - 2: Delete a contact specified in the data field

    - 3: Upload message history (recipient info and message content)

    - 5: Upload image files

    - 8: Force-send a message with the content to a specified phone number

    - 24: Upload information on all installed apps (icon, app name, version, package name, install time, update time)

    - 30: Add contact information as specified in name and phoneNum fields

    - 41: Upload current volume information

    - 42: Mute or set volume to 5 based on the data field value

    - 44: Upload account information



✅ Recommended Threat Detection and Mitigation Measures:


- For a comprehensive analysis and specific mitigation measures against smishing apps, please contact through the link below.



🧑‍💻 Report Author: S2W TALON


👉 For inquiries about the full report: https://s2w.inc/en/contact




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