Call Control

What the technique is

Adversaries may make, forward, or block phone calls without user authorization. This could be used for adversary goals such as audio surveillance, blocking or forwarding calls from the device owner, or C2 communication. Several permissions may be used to programmatically control phone calls, including: ANSWER_PHONE_CALLS - Allows the application to answer incoming phone calls CALL_PHONE - Allows the application to initiate a phone call without going through the Dialer interface PROCESS_OUTGOING_CALLS - Allows the application to see the number being dialed during an outgoing call with the option to redirect the call to a different number or abort the call altogether MANAGE_OWN_CALLS - Allows a calling application which manages its own calls through the self-managed ConnectionService APIs BIND_TELECOM_CONNECTION_SERVICE - Required permission when using a ConnectionService WRITE_CALL_LOG - Allows an application to write to the device call log, potentially to hide malicious phone calls When granted some of these permissions, an application can make a phone call without opening the dialer first. However, if an application desires to simply redirect the user to the dialer with a phone number filled in, it can launch an Intent using Intent.ACTION_DIAL, which requires no specific permissions. […]

What MITRE says you would watch

• AN1822

  The defender correlates call-control capability or telecom role state with subsequent unauthorized call initiation, answer, block, redirect, or concealment behavior by an application outside expected telephony workflows. The analytic prioritizes Android-observable control-plane effects: dangerous or role-gated call-control permissions, default dialer or ConnectionService-related role changes, telecom framework invocation for call placement or handling, write activity against call-log records, and call-control activity occurring from background or locked-device context without recent user interaction.