CyberCertPrepMobile Security FundamentalsMobile Threats & MalwareEASYFree question
A mobile malware sample sends a premium-rate SMS to a number controlled by the attacker immediately after installation without user interaction. The victim receives an unexpected charge on their phone bill. What malware category and technical mechanism describes this attack?
- A.Ransomware using SMS for its command channel while it encrypts the device storage behind a lock screen the victim is unable to dismiss
- B.Toll fraud malware exploiting the CALL_PHONE permission to place premium-rate calls in the background while the screen is off
- C.Subscription scam malware using WAP billing triggered from a hidden WebView
- D.Premium SMS fraud malware using the SEND_SMS permission to silently send chargeable messages to premium-rate numbers
Why D is correct
Premium SMS fraud malware uses the SEND_SMS permission to send text messages to premium-rate shortcodes (numbers where each SMS incurs a charge billed to the sender). The attacker controls the premium number and collects the revenue. This is distinct from toll fraud (which uses CALL_PHONE for premium calls) and WAP billing (which uses a background WebView HTTP request to subscribe the victim, not SMS). This is also distinct from ransomware which encrypts data.
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