Konfety Returns: Classic Mobile Threat with New Evasion Techniques

The Konfety Android malware uses advanced evasion techniques such as ZIP-level tampering, dynamic code loading, and stealth features to conduct large-scale ad fraud and distribute malicious payloads. It mimics legitimate apps by sharing package names and hides its presence, while redirecting users to harmful websites and triggering persistent unwanted notifications. #Konfety #CaramelAds

Keypoints

  • Konfety employs a dual-app deception by sharing the same package name between benign and malicious variants to evade detection.
  • The malware uses ZIP-level evasion techniques such as enabling General Purpose Flags and unsupported BZIP compression to disrupt analysis tools.
  • Dynamic code loading with encrypted secondary DEX files hides core malicious functionality until runtime.
  • Stealth tactics include hiding the app icon, geofencing based on user location, and mimicking legitimate apps to avoid suspicion.
  • Konfety abuses the CaramelAds SDK to fetch ads, deliver payloads, and maintain communication with attacker-controlled servers.
  • The malware redirects users to fraudulent websites prompting unwanted app installs and persistent spam-like browser notifications.
  • Zimperium’s Mobile Threat Defense solutions effectively detect and mitigate Konfety’s advanced evasion methods.

MITRE Techniques

  • [T1624.001] Event Triggered Execution: Broadcast Receivers – Creates broadcast receivers to receive network events.
  • [T1655.001] Masquerading: Match Legitimate Name or Location – Uses package names of legitimate decoy apps from the Google Play Store.
  • [T1627.001] Geofencing – Redirects victims detected as from EU countries to suspicious sites, others to google.com.
  • [T1628.001] Suppress Application Icon – Hides the app icon from the user.
  • [T1406.002] Obfuscated Files or Information: Software Packing – Uses dynamic class loading and obfuscation to conceal code.
  • [T1420] File and Directory Discovery – Searches for the pattern “@injseq” within files.
  • [T1418] Software Discovery – Collects installed application package lists to check for specific apps.
  • [T1422] System Network Configuration Discovery – Collects network information from the device.
  • [T1426] System Information Discovery – Gathers basic device information.
  • [T1481.001] Dead Drop Resolver – Connects to websites that redirect victims to multiple addresses.

Indicators of Compromise

  • [Domain] Command and control server domain involved in redirects – push.razkondronging.com
  • [File Names] Package name shared by both benign and malicious variants used as decoys.
  • [Network] URLs involved in redirection and payload delivery – multiple redirect websites after initial contact.
  • [Code Patterns] Regular expression pattern searched by malware – “@injseq”.


Read more: https://zimperium.com/blog/konfety-returns-classic-mobile-threat-with-new-evasion-techniques