Process Injection Techniques
Overview
Process injection techniques involve an adversary inserting malicious code into the address space of another process to execute code stealthily. This approach enables attackers to evade detection, maintain persistence, and escalate privileges by leveraging legitimate processes. Process injection is commonly employed during execution, persistence, and defense evasion stages of the attack lifecycle.
Attack Objective
- Gain stealthy code execution and control over system processes
- Supports Execution, Persistence, Privilege Escalation, and Defense Evasion stages
- Advances attacker position by hiding malicious activity within trusted processes and bypassing security controls
How the Technique Works
Process injection works by manipulating the memory or execution context of a legitimate process to run attacker-controlled code. This can involve writing shellcode into another process’s memory, hijacking threads, or altering process entry points. The injected code executes with the privileges of the host process, allowing attackers to blend their actions with normal system operations.
Common Methods & Variations
- Classic DLL injection, reflective DLL injection, and code cave injection
- Remote thread injection, process hollowing, and thread hijacking
- Variants targeting on-premises endpoints, cloud workloads, and identity tokens
- Use of living-off-the-land binaries (LOLBins) versus custom or third-party tools
Indicators of Compromise (IOCs)
- Unexpected process behavior such as anomalous memory allocations or thread creation
- Suspicious API calls related to memory manipulation and thread control in logs
- Unusual parent-child process relationships and process injection artifacts on endpoints
- Network anomalies from injected processes communicating with external infrastructure
Detection Strategies
- Monitoring endpoint telemetry for process creation, memory writes, and thread injections
- Behavioral detection focusing on anomalous process interactions rather than static signatures
- Correlation of process anomalies with network activity and user behavior analytics
Mitigation & Prevention
- Implement application whitelisting and restrict code execution privileges
- Harden process permissions and enable exploit mitigation features like DEP and ASLR
- Enforce least privilege principles and monitor for misuse of administrative credentials
Response Considerations
- Isolate affected systems to prevent lateral movement
- Conduct memory forensics and process analysis to identify injected code and entry points
- Remove malicious code, patch vulnerabilities, and strengthen endpoint defenses post-incident
Related Techniques
- Process Hollowing and DLL Side-Loading as complementary execution methods
- Credential Dumping and Privilege Escalation techniques often follow injection
- Command and Control channels established through injected processes
Mapping & References
- MITRE ATT&CK Techniques: T1055 (Process Injection), with sub-techniques such as T1055.001 (DLL Injection), T1055.003 (Thread Execution Hijacking)
- Public research and advisories on process injection detection and mitigation from cybersecurity vendors and CERTs