The Dark Side of EDR: Repurpose EDR as an Offensive Tool

EDR solutions require three key properties to function effectively: highest possible privileges, tamper-proof files, and strong persistence mechanisms

Main vulnerabilities found in EDR implementation:

• Clear text policy rules and configuration files
• Heavy reliance on process name matching for whitelisting
• Insufficient protection against file linking techniques
• Simple regex-based detection that can be bypassed
• Lack of encryption for sensitive configuration files

Key attack vectors demonstrated:

• Using hard links to modify protected EDR files
• Bypassing process name checks by renaming malicious tools
• Modifying EDR policy rules to allow malicious actions
• Exploiting EDR’s own high privileges for malware execution
• Injecting malicious code into EDR’s trusted processes

Critical security design flaws:

• Storing detection logic and rules in readable format
• Whitelisting processes based only on names
• Insufficient protection of configuration files
• Vulnerable update/check-in mechanisms

Recommended mitigations:

• Encrypt policy files and rules
• Implement stronger file protection beyond path checks
• Use multiple parameters for process validation
• Add better integrity checks for content files
• Improve protection of EDR’s self-defense mechanisms

Once compromised, EDR’s own protective features (persistence, privileges, stealth) can be weaponized by attackers