T1211 Exploitation for Defense Evasion

High-Level Description

Adversaries may exploit a system or application vulnerability to bypass security features. Exploitation of a vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. Vulnerabilities may exist in defensive security software that can be used to disable or circumvent them.

Adversaries may have prior knowledge through reconnaissance that security software exists within an environment or they may perform checks during or shortly after the system is compromised for Security Software Discovery. The security software will likely be targeted directly for exploitation. There are examples of antivirus software being targeted by persistent threat groups to avoid detection.

There have also been examples of vulnerabilities in public cloud infrastructure of SaaS applications that may bypass defense boundaries , evade security logs , or deploy hidden infrastructure.

Kill Chain Phase

• Defense Evasion (TA0005)

Platforms: Linux, Windows, macOS, SaaS, IaaS

What to Check

• ] Identify if Exploitation for Defense Evasion technique is applicable to target environment
• ] Check Linux systems for indicators of Exploitation for Defense Evasion
• ] Check Windows systems for indicators of Exploitation for Defense Evasion
• ] Check macOS systems for indicators of Exploitation for Defense Evasion
• ] Verify mitigations are bypassed or absent (4 known mitigations)
• ] Assess detection coverage (1 detection strategies)

How to Test

Manual Testing

1. Identify Attack Surface: Determine if the target environment is susceptible to Exploitation for Defense Evasion by examining the target platforms (Linux, Windows, macOS).

1. Assess Existing Defenses: Review whether mitigations for T1211 are in place. If defenses are absent or misconfigured, this technique may be exploitable.

1. Execute Test: Use tools and methods described in the MITRE ATT&CK page and external references below.

> Note: No Atomic Red Team tests available for this technique. See Atomic Red Team GitHub for updates.

Remediation Guide

M1050 Exploit Protection

Security applications that look for behavior used during exploitation such as Windows Defender Exploit Guard (WDEG) and the Enhanced Mitigation Experience Toolkit (EMET) can be used to mitigate some exploitation behavior. Control flow integrity checking is another way to potentially identify and stop a software exploit from occurring. Many of these protections depend on the architecture and target application binary for compatibility and may not work for software targeted for defense evasion.

M1051 Update Software

Update software regularly by employing patch management for internal enterprise endpoints and servers.

M1019 Threat Intelligence Program

Develop a robust cyber threat intelligence capability to determine what types and levels of threat may use software exploits and 0-days against a particular organization.

M1048 Application Isolation and Sandboxing

Make it difficult for adversaries to advance their operation through exploitation of undiscovered or unpatched vulnerabilities by using sandboxing. Other types of virtualization and application microsegmentation may also mitigate the impact of some types of exploitation. Risks of additional exploits and weaknesses in these systems may still exist.

Detection

Detection Strategy for Exploitation for Defense Evasion

Risk Assessment

| Finding | Severity | Impact | | ----------------------------------------------------- | -------- | --------------- | | Exploitation for Defense Evasion technique applicable | High | Defense Evasion |

CWE Categories

| CWE ID | Title | | ------- | ---------------------------- | | CWE-693 | Protection Mechanism Failure |

References

• Salesforce zero-day in facebook phishing attack
• Bypassing CloudTrail in AWS Service Catalog
• GhostToken GCP flaw
• Atomic Red Team - T1211
• MITRE ATT&CK - T1211