T1632.001Not expressible in SigmaMOBILE

Code Signing Policy Modification

Defense EvasionAndroid, iOS

Where this stands

No Sigma rule can address this — the telemetry MITRE names has no Sigma logsource behind it.

Sigma has no logsource taxonomy for mobile platforms. MITRE's telemetry here is mobile EDR and device APIs, which no Sigma rule can address.

What the technique is

Adversaries may modify code signing policies to enable execution of applications signed with unofficial or unknown keys. Code signing provides a level of authenticity on an app from a developer, guaranteeing that the program has not been tampered with and comes from an official source. Security controls can include enforcement mechanisms to ensure that only valid, signed code can be run on a device. Mobile devices generally enable these security controls by default, such as preventing the installation of unknown applications on Android. Adversaries may modify these policies in a number of ways, including Input Injection or malicious configuration profiles.

Read it on attack.mitre.org

What MITRE says you would watch

AN1679
On Android, the user can use the device settings menu to view trusted CA certificates and look for unexpected or unknown certificates. A mobile security product could similarly examine the trusted CA certificate store for anomalies. Users can use the device settings menu to view which applications on the device are allowed to install unknown applications. On iOS, the user can use the device settings menu to view installed Configuration Profiles and look for unexpected or unknown profiles. A Mobile Device Management (MDM) system could use the iOS MDM APIs to examine the list of installed Configuration Profiles for anomalies.
AN1680
On Android, the user can use the device settings menu to view trusted CA certificates and look for unexpected or unknown certificates. A mobile security product could similarly examine the trusted CA certificate store for anomalies. Users can use the device settings menu to view which applications on the device are allowed to install unknown applications. On iOS, the user can use the device settings menu to view installed Configuration Profiles and look for unexpected or unknown profiles. A Mobile Device Management (MDM) system could use the iOS MDM APIs to examine the list of installed Configuration Profiles for anomalies.