Vietnamese hackers attack Bengaluru users with fake e-challans on WhatsApp, mimicking Karnataka Police or Parivahan Sewa. Gujarat and Karnataka are significantly affected. The Wromba malware has infected 4,400+ devices, causing Rs 16 lakh in fraud. Malware requests extensive app permissions. Use Google Play Store, update systems, review permissions, check genuine e-challans for vehicle registration numbers, and report to authorities.