# IR-4(12)_malicious-code-and-forensic-analysis

> Analyze malicious code and/or other residual artifacts remaining in the system after the incident.

- Skill: `cyberstrikeus/ir-4-12-malicious-code-and-forensic-analysis` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/ir-4-12-malicious-code-and-forensic-analysis`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/ir-4-12-malicious-code-and-forensic-analysis/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/ir-4-12-malicious-code-and-forensic-analysis

---


# IR-4(12) Malicious Code and Forensic Analysis

> **Enhancement of:** IR-4

## High-Level Description

**Family:** Incident Response (IR)
**Framework:** NIST SP 800-53 Rev 5

When conducted carefully in an isolated environment, analysis of malicious code and other residual artifacts of a security incident or breach can give the organization insight into adversary tactics, techniques, and procedures. It can also indicate the identity or some defining characteristics of the adversary. In addition, malicious code analysis can help the organization develop responses to future incidents.

## What to Check

- [ ] Verify IR-4(12) Malicious Code and Forensic Analysis is documented in SSP
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for IR-4(12)
- [ ] Verify enhancement builds upon base control IR-4

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for IR-4(12) implementation details. Verify the organization has documented how this control is satisfied.

### Step 2: Validate Implementation

```
# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null
```

### Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

## Tools

| Tool          | Purpose                           | Usage |
| ------------- | --------------------------------- | ----- |
| Manual Review | Documentation and interview-based | N/A   |

## Remediation Guide

### Control Statement

Analyze malicious code and/or other residual artifacts remaining in the system after the incident.

### Implementation Guidance

When conducted carefully in an isolated environment, analysis of malicious code and other residual artifacts of a security incident or breach can give the organization insight into adversary tactics, techniques, and procedures. It can also indicate the identity or some defining characteristics of the adversary. In addition, malicious code analysis can help the organization develop responses to future incidents.

## Risk Assessment

| Finding                                                       | Severity | Impact                       |
| ------------------------------------------------------------- | -------- | ---------------------------- |
| IR-4(12) Malicious Code and Forensic Analysis not implemented | Medium   | Incident Response            |
| IR-4(12) partially implemented                                | Low      | Incomplete Incident Response |

## CWE Categories

| CWE ID | Title                 |
| ------ | --------------------- |
| N/A    | No direct CWE mapping |

## References

- [NIST SP 800-53 Rev 5 - IR-4(12)](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=ir-4.12)
- [NIST SP 800-53A Rev 5 (Assessment Procedures)](https://csrc.nist.gov/pubs/sp/800/53/a/r5/final)
- [NIST SP 800-53 Rev 5 Full Catalog](https://csrc.nist.gov/pubs/sp/800/53/r5/upd1/final)

## Checklist

- [ ] Control documented in SSP
- [ ] Implementation evidence collected
- [ ] Operating effectiveness validated
- [ ] Continuous monitoring in place
- [ ] Related controls (none) reviewed