# Static vs. Dynamic Analysis

> Compare static and dynamic file analysis approaches: how each works, their strengths and limitations, and how ReversingLabs products combine both for comprehensive threat detection.

# Static vs. Dynamic Analysis

File analysis for malware detection uses two complementary approaches: static analysis and dynamic analysis. Understanding the difference helps security teams choose the right tool for each investigation and interpret results correctly.

## Static analysis

Static analysis examines a file's structure, code, and metadata without executing it. The analysis engine unpacks the file, parses its format, extracts strings and metadata, and compares patterns against known threat indicators.

**How it works in ReversingLabs products:**
[Spectra Core](/General/AnalysisAndClassification/SpectraCoreAnalysis) performs static analysis across all ReversingLabs products. It unpacks containers, archives, and packed executables recursively — handling over 400 file formats — and extracts indicators such as imported functions, embedded URLs, certificate data, and YARA rule matches.

**Strengths:**
- Fast — typically completes in seconds
- Deterministic — same file always produces the same result
- Safe — no execution environment required
- Scales to millions of files per day
- Effective against known malware families and obfuscated variants

**Limitations:**
- Cannot observe runtime behavior (network connections, process creation, registry changes)
- Heavily obfuscated or encrypted payloads may yield fewer indicators
- May not detect malware that only activates under specific conditions

## Dynamic analysis

Dynamic analysis executes a file in an isolated sandbox environment and monitors its behavior. Behavioral indicators include file system changes, registry modifications, network connections, and process activity.

**How it works in ReversingLabs products:**
[Spectra Analyze](/SpectraAnalyze/) integrates with sandbox environments to provide dynamic analysis alongside static results. Combined reports include both static indicators from Spectra Core and behavioral indicators from sandbox execution.

**Strengths:**
- Reveals runtime behavior invisible to static analysis
- Effective against encrypted payloads that decrypt only at runtime
- Detects fileless malware and in-memory threats
- Provides network IOCs (C2 domains, IP addresses)

**Limitations:**
- Slower — execution and observation take minutes per file
- Sandbox evasion techniques can suppress malicious behavior
- Not suitable for high-throughput scanning pipelines
- Some file types (firmware, specialized formats) may not execute correctly in generic sandboxes

## Comparison

| | Static Analysis | Dynamic Analysis |
|---|---|---|
| Speed | Seconds | Minutes |
| Throughput | Millions/day | Hundreds/day |
| Execution required | No | Yes |
| Behavioral indicators | No | Yes |
| Sandbox evasion risk | None | Yes |
| File format coverage | 400+ formats | Limited by sandbox OS |
| Best for | High-volume triage, known malware | Deep investigation, unknown samples |

## How ReversingLabs combines both

ReversingLabs products use static analysis as the primary, high-speed triage layer and dynamic analysis for deeper investigation of suspicious samples:

1. **Triage with static analysis** — [Spectra Detect](/SpectraDetect/) and [File Inspection Engine](/FileInspectionEngine/) use Spectra Core static analysis to process files at scale, flagging malicious and suspicious files within seconds.
2. **Investigate with dynamic analysis** — Spectra Analyze enriches static results with sandbox behavioral analysis for samples requiring deeper investigation.
3. **Correlate indicators** — Both static and dynamic results map to [MITRE ATT&CK](https://attack.mitre.org/) tactics and techniques for threat correlation.

## Key takeaways

- Static analysis is fast, scalable, and sufficient for most known threats
- Dynamic analysis adds behavioral depth for unknown or evasive malware
- Use both together for comprehensive coverage
- ReversingLabs Spectra Core handles static analysis; Spectra Analyze integrates dynamic analysis for investigation workflows

## Related documentation

- [Spectra Core Analysis](/General/AnalysisAndClassification/SpectraCoreAnalysis) — deep dive into static analysis capabilities
- [Classification](/General/AnalysisAndClassification/Classification) — how static and dynamic results contribute to the final verdict
- [Spectra Analyze](/SpectraAnalyze/) — platform that supports both approaches
