Defense Evasion

Defense evasion consists of techniques an adversary may use to evade detection or avoid other defenses. Sometimes these actions are the same as or variations of techniques in other categories that have the added benefit of subverting a particular defense or mitigation. Defense evasion may be considered a set of attributes the adversary applies to all other phases of the operation.
ID: TA0030

Techniques

Techniques: 8
IDNameDescription
T1418Application Discovery

Adversaries may seek to identify all applications installed on the device. One use case for doing so is to identify the presence of endpoint security applications that may increase the adversary's risk of detection. Another use case is to identify the presence of applications that the adversary may wish to target.

T1408Disguise Root/Jailbreak Indicators

An adversary could use knowledge of the techniques used by security software to evade detection. For example, some mobile security products perform compromised device detection by searching for particular artifacts such as an installed "su" binary, but that check could be evaded by naming the binary something else. Similarly, polymorphic code techniques could be used to evade signature-based detection.

T1407Download New Code at Runtime

An app could download and execute dynamic code (not included in the original application package) after installation to evade static analysis techniques (and potentially dynamic analysis techniques) used for application vetting or application store review.

T1478Install Insecure or Malicious Configuration

An adversary could attempt to install insecure or malicious configuration settings on the mobile device, through means such as phishing emails or text messages either directly containing the configuration settings as an attachment, or containing a web link to the configuration settings. The device user may be tricked into installing the configuration settings through social engineering techniques .

T1398Modify OS Kernel or Boot Partition

If an adversary can escalate privileges, he or she may be able to use those privileges to place malicious code in the device kernel or other boot partition components, where the code may evade detection, may persist after device resets, and may not be removable by the device user. In some cases (e.g., the Samsung Knox warranty bit as described under Detection), the attack may be detected but could result in the device being placed in a state that no longer allows certain functionality.

T1400Modify System Partition

If an adversary can escalate privileges, he or she may be able to use those privileges to place malicious code in the device system partition, where it may persist after device resets and may not be easily removed by the device user.

T1399Modify Trusted Execution Environment

If an adversary can escalate privileges, he or she may be able to use those privileges to place malicious code in the device's Trusted Execution Environment (TEE) or other similar isolated execution environment where the code can evade detection, may persist after device resets, and may not be removable by the device user. Running code within the TEE may provide an adversary with the ability to monitor or tamper with overall device behavior.

T1406Obfuscated Files or Information

An app could contain malicious code in obfuscated or encrypted form, then deobfuscate or decrypt the code at runtime to evade many app vetting techniques.