Listen to this Post
Introduction
A sophisticated Android banking malware—dubbed “KYCShadow”—is actively targeting users in India by masquerading as a legitimate “Banking KYC” verification application. Delivered via deceptive WhatsApp messages, the campaign uses urgency and social engineering to trick victims into installing a malicious APK that ultimately hijacks bank accounts. By employing a multi-stage dropper architecture, native-code obfuscation, and full-device VPN hijacking, this malware establishes persistence, intercepts SMS OTPs, manipulates calls, and exfiltrates sensitive financial credentials directly to a command-and-control (C2) server.
Learning Objectives
- Objective 1 – Understand the technical anatomy of a multi-stage Android dropper and how native code obfuscation evades static analysis.
- Objective 2 – Learn to identify Indicators of Compromise (IOCs) and perform basic static/dynamic analysis of suspicious APK files.
- Objective 3 – Implement defensive configurations on Android devices and enterprise environments to block sideloaded malware.
You Should Know
1. Multi-Stage Dropper Analysis & Native Obfuscation
The primary KYCShadow app (com.appad.andr) is a lightweight loader, not the main infostealer. Upon installation, a non-exported receiver (InstallReceiver) listens for `PACKAGE_ADDED` events. It embeds an encrypted APK asset, derives a 32-byte XOR key from its own package name, dynamically decrypts the payload, and silently deploys a secondary package (com.am5maw3.android) using Android’s `PackageInstaller` session API—bypassing typical installation friction on modern Android versions.
The real sophistication lies in the native library (libnative-lib.so). Critical C2 configurations—such as the backend URL https://jsonapi[.]biz` and agent IDXGEKKWB3`—are not present in decompiled Java bytecode. Instead, they are assembled character-by-character at runtime via JNI calls, rendering traditional static analysis ineffective.
Step‑by‑step guide to analyze such an APK (using Linux):
1. Decompile the APK with apktool and jadx apktool d suspect.apk -o decompiled_source/ jadx -d jadx_output suspect.apk <ol> <li>Inspect AndroidManifest.xml for suspicious permissions & receivers cat decompiled_source/AndroidManifest.xml | grep -E "(RECEIVE_BOOT_COMPLETED|READ_SMS|INTERNET|REQUEST_INSTALL_PACKAGES)"</p></li> <li><p>Extract and analyze native libraries unzip suspect.apk -d apk_extract/ file apk_extract/lib/armeabi-v7a/libnative-lib.so strings apk_extract/lib/armeabi-v7a/libnative-lib.so | grep -E "https?://|XGEKK"</p></li> <li><p>Use androguard to examine dangerous permission combos python3 -m androguard analyze suspect.apk Within androguard shell: a.get_permissions()
Windows alternative (using MobSF in Docker):
docker pull opensecurity/mobile-security-framework-mobsf docker run -it -p 8000:8000 opensecurity/mobile-security-framework-mobsf Upload suspect.apk via http://localhost:8000 for automated static/dynamic analysis
2. Network Forensics & VPN Hijacking Detection
Once installed, KYCShadow registers a `SecureVpnService` that configures a full-tunnel VPN with a local address `10.0.0.2` and Google DNS (8.8.8.8), forcing all device traffic through an application-controlled interface. This allows the malware to inspect, filter, or disrupt outbound connections—including telemetry to Google Play Protect, effectively neutralizing cloud-based reputation defenses. Incoming FCM messages are routed to AgentCore.ProcessCommand, which supports operations such as SET_SMS_FORWARD, GET_SMS_LOGS, MAKE_CALL, RUN_USSD, and SEND_SMS.
Step‑by‑step guide to detect and monitor VPN hijacking:
On the compromised Android device (via ADB shell) adb shell dumpsys netstats | grep -A 10 "iface=wlan0" adb shell netstat -an | grep -E "10.0.0.2|jsonapi.biz" adb shell logcat -b all | grep -i "securevpnservice" Monitor DNS queries (requires rooted device or custom VPN) adb shell tcpdump -i any -n -s 0 -w /sdcard/capture.pcap Pull and analyze the pcap on your analysis machine adb pull /sdcard/capture.pcap . tshark -r capture.pcap -Y "dns.qry.name contains jsonapi.biz" -T fields -e ip.src -e dns.qry.name
Extracted IOCs (to block at network/firewall level):
- C2 Domains:
jsonapi[.]biz,jsonserv[.]biz, `jsonserv[.]xyz` - Malicious Package Name (secondary payload): `com.am5maw3.android`
3. Android Security Hardening (2026 Update)
Google has introduced “Advanced Flow” for sideloaded APK installations, requiring a mandatory 24-hour wait period for apps from unverified developers. Additionally, Android 16’s Advanced Protection Mode blocks all sideloading, restricts USB data signaling, and enforces always-on malware scanning. Enterprise administrators should enforce MDM policies that restrict installations exclusively to the Google Play Store and approved enterprise stores.
Recommended user & corporate configurations:
On Android device (via ADB or manually) Settings → Security → Advanced Protection → Enable (Android 16+) Settings → Google → Play Protect → Turn on "Improve harmful app detection" Settings → Apps → Special app access → Install unknown apps → Block all untrusted sources For enterprise (via ADB programmatically) adb shell settings put global verifier_verify_adb_installs 1 adb shell settings put global package_verifier_enable 1 adb shell pm disable-user --user 0 com.android.documentsui Restricts file manager sideloading
Windows command to audit sideloading policy (via Intune/Graph API):
Requires Microsoft Graph PowerShell SDK
Connect-MgGraph -Scopes "DeviceManagementConfiguration.Read.All"
Get-MgDeviceManagementDeviceConfiguration | Where-Object {$_.AdditionalProperties.'@odata.type' -eq 'microsoft.graph.androidDeviceOwnerGeneralDeviceConfiguration'}
4. Incident Response & APK Static Analysis Toolkit
When a compromised device is suspected, immediate isolation from the network is critical. The following commands help enumerate malicious packages, extract logs, and gather forensic artifacts for further analysis.
Step‑by‑step incident response on a potentially infected Android device (Linux/macOS):
1. List all installed packages (identify suspicious ones) adb shell pm list packages | grep -v "com.google|com.android|com.samsung" <ol> <li>Check for packages with REQUEST_INSTALL_PACKAGES permission adb shell pm list permissions -g -d | grep -B 5 "INSTALL_PACKAGES"</p></li> <li><p>Extract running processes and network connections adb shell ps -A | grep -E "appad|am5maw3" adb shell netstat -an | grep ESTABLISHED</p></li> <li><p>Pull SMS/MMS databases (requires root or backup) adb exec-out run-as com.android.providers.telephony cat databases/mmssms.db > mmssms.db</p></li> <li><p>Retrieve system logs for forensic timestamping adb logcat -b all -d > full_logcat.txt adb shell dumpsys battery > battery_history.txt Helps establish timeline</p></li> <li><p>Generate a forensic report with MVT (Mobile Verification Toolkit) mvt-android check-adb --output /tmp/forensic_report/
- Cloud Hardening & API Security for Banking Apps
Banking institutions should implement runtime application self-protection (RASP) and certificate pinning to mitigate overlay attacks and API abuse. KYCShadow’s ability to intercept OTPs highlights the need for additional out-of-band verification mechanisms.
Example API security configuration (NGINX reverse proxy for banking backend):
Block known malicious user-agents and enforce TLS 1.3
if ($http_user_agent ~ (KYCShadow|malware)) { return 403; }
ssl_protocols TLSv1.3;
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
Rate limit sensitive endpoints (e.g., /api/kyc/verify)
limit_req_zone $binary_remote_addr zone=kyc_api:10m rate=5r/m;
location /api/kyc/verify {
limit_req zone=kyc_api burst=3 nodelay;
proxy_pass https://banking_backend;
}
What Undercode Say:
- Key Takeaway 1 – Social engineering remains the primary infection vector; no technical control can substitute for user awareness training regarding unsolicited APK files.
- Key Takeaway 2 – Multi-stage droppers combined with native-code obfuscation effectively bypass traditional signature-based AV and static analysis tools—demanding runtime behavioral detection.
In the ongoing arms race between malware authors and defenders, KYCShadow demonstrates a worrying trend: blending legitimate system features (VPN, FCM, PackageInstaller) with sophisticated evasion techniques. Organizations must shift from reactive to proactive mobile security postures, leveraging runtime monitoring, behavioral analytics, and mandatory sideloading restrictions. Users must be repeatedly educated that banks never send KYC links via WhatsApp. As Google’s 24-hour unverified app delay and Advanced Protection Mode roll out globally, the window for such attacks will shrink—but social engineering will always find a way.
Prediction: By Q4 2026, we will see a 300% increase in Android malware utilizing native-code obfuscation and legitimate cloud messaging services (FCM, Firebase) for covert C2 communication. Concurrently, enterprise adoption of Android 16’s Advanced Protection Mode will reduce successful sideloaded malware infections by 60%, shifting attacker focus toward exploiting OEM pre-installed apps and firmware-level vulnerabilities.
▶️ Related Video (84% Match):
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: Cybersecuritynews Gbhackers – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
