Detecting T1055 Process Injection With Sysmon

Detecting T1055 Process Injection With Sysmon

Overview

Cybersecurity skill for detecting t1055 process injection with sysmon. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "detecting t1055 process injection with sysmon"

• "Detect process injection techniques (T1055) including classic DLL injection, pro"

• When hunting for defense evasion techniques that hide malicious code inside legitimate processes

• After EDR alerts for suspicious cross-process memory access or remote thread creation

• When investigating malware that injects into svchost.exe, explorer.exe, or other system processes

• During purple team exercises testing detection of process injection variants

• When validating Sysmon configuration coverage for injection detection

When NOT to Use

• When you lack proper authorization for testing
• For production systems without change management
• When the task requires legal or compliance expertise beyond technical scope

Prerequisites

• Sysmon deployed with comprehensive configuration capturing Events 1, 7, 8, 10, 25
• Event ID 8 (CreateRemoteThread) enabled for remote thread detection
• Event ID 10 (ProcessAccess) configured with appropriate access mask filters
• Event ID 7 (ImageLoaded) for DLL injection detection
• Event ID 25 (ProcessTampering) for process hollowing on Sysmon 13+
• SIEM platform for correlation and alerting

Workflow

# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}

1. Define Detection Scope — Identify the specific t1055 process injection techniques or indicators to hunt. Map to MITRE ATT&CK tactics/techniques where applicable.
2. Collect Baseline Data — Gather historical logs and establish normal behavior patterns for t1055 process injection.
3. Build Detection Queries — Write sysmon queries targeting t1055 process injection indicators. Use platform-specific query language for optimal performance.
4. Execute Hunts — Run queries against the collected data, starting with broad filters and narrowing down.
5. Triage Results — Investigate alerts, filter false positives, and validate findings against known-good behavior.
6. Document Findings — Record confirmed detections, IOCs, and affected systems. Update detection rules based on findings.

Tools

• sysmon — Primary tool for this skill
• SIEM Platform — Central log aggregation and query execution
• Sigma Rules — Vendor-agnostic detection rule format
• MITRE ATT&CK Navigator — Technique mapping and coverage analysis

Process

1. Reconnaissance — Gather target information, identify attack surface, enumerate services
2. Analysis/Exploitation — Execute the technique, analyze results, document findings
3. Reporting — Document IOCs, write findings, provide remediation recommendations

Verification

• All t1055 process injection procedures executed completely and documented
• Findings validated against multiple data sources
• False positives identified and filtered
• Results documented with evidence and timestamps
• Recommendations provided with risk-based prioritization

Anti-Rationalization Table