T1638Not expressible in SigmaMOBILE

Adversary-in-the-Middle

CollectionAndroid, 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 attempt to position themselves between two or more networked devices to support follow-on behaviors such as Transmitted Data Manipulation or Endpoint Denial of Service. Adversary-in-the-Middle can be achieved through several mechanisms. For example, a malicious application may register itself as a VPN client, effectively redirecting device traffic to adversary-owned resources. Registering as a VPN client requires user consent on both Android and iOS; additionally, a special entitlement granted by Apple is needed for iOS devices. Alternatively, a malicious application with escalation privileges may utilize those privileges to gain access to network traffic. Specific to Android devices, adversary-in-the-disk is a type of AiTM attack where adversaries monitor and manipulate data that is exchanged between applications and external storage. To accomplish this, a malicious application firsts requests for access to multimedia files on the device (READ_EXTERNAL STORAGE and WRITE_EXTERNAL_STORAGE), then the application reads data on the device and/or writes malware to the device. Though the request for access is common, when used maliciously, adversaries may access files and other sensitive data due to abusing the permission. […]

Read it on attack.mitre.org

What MITRE says you would watch

AN1687
Mobile security products can potentially detect rogue Wi-Fi access points if the adversary is attempting to decrypt traffic using an untrusted SSL certificate. Application vetting services should look for applications that request VPN access. These applications should be heavily scrutinized since VPN functionality is not very common. On both Android and iOS, the user must grant consent to an application to act as a VPN. Both platforms also provide visual context to the user in the top status bar when a VPN connection is active. The user can see registered VPN services in the device settings.
AN1688
Mobile security products can potentially detect rogue Wi-Fi access points if the adversary is attempting to decrypt traffic using an untrusted SSL certificate. Application vetting services should look for applications that request VPN access. These applications should be heavily scrutinized since VPN functionality is not very common. On both Android and iOS, the user must grant consent to an application to act as a VPN. Both platforms also provide visual context to the user in the top status bar when a VPN connection is active. The user can see registered VPN services in the device settings.