Malware Analysis

What Is Malware Analysis?

Malware analysis is the process of examining malicious code to understand its behavior, capabilities, origin, and objectives. It is essential for incident response, threat intelligence, and the development of effective countermeasures.

Types of Analysis

1. Static Analysis

Examination of the malware without executing it:

  • String and metadata analysis
  • Identification of packers and obfuscation
  • PE/ELF header analysis
  • Signatures and hashes (MD5, SHA-256, SSDEEP)
  • YARA rules matching

2. Dynamic Analysis

Controlled execution in an isolated environment:

  • Sandbox analysis (Cuckoo, Any.Run, Joe Sandbox)
  • System call monitoring
  • Network traffic analysis
  • Filesystem and registry modifications
  • Spawned processes and code injection

3. Reverse Engineering

In-depth code analysis:

  • Disassembly and decompilation
  • Debugging and flow analysis
  • Identification of cryptographic algorithms
  • Extraction of configurations and IOCs

Essential Tools

Static Analysis

  • • PEiD / Detect It Easy
  • • PEStudio / CFF Explorer
  • • Strings / FLOSS
  • • VirusTotal / Hybrid Analysis
  • • YARA / Capa

Dynamic Analysis

  • • Cuckoo Sandbox
  • • Any.Run
  • • Process Monitor (Sysinternals)
  • • Wireshark / tcpdump
  • • Regshot

Reverse Engineering

  • • IDA Pro / Ghidra
  • • x64dbg / WinDbg
  • • dnSpy (for .NET)
  • • JD-GUI (for Java)
  • • Radare2

Memory and Forensics

  • • Volatility Framework
  • • Rekall
  • • SANS SIFT Workstation
  • • REMnux Distribution

Analysis Methodology

Phase 1: Initial Triage

  • Calculate hashes and check them against threat intelligence databases
  • Submit to public sandboxes (VirusTotal, Hybrid Analysis)
  • Quick analysis of strings and imports
  • Determine file type and possible packer

Phase 2: Behavioral Analysis

  • Execute in a controlled sandbox
  • Monitor file and process creation
  • Capture network traffic and C2 connections
  • Identify persistence techniques

Phase 3: In-Depth Analysis

  • Unpacking and deobfuscation
  • Reverse engineering of critical functions
  • Extraction of configurations and IOCs
  • Identification of families and variants

Indicators of Compromise (IOCs)

Essential IOCs to extract:

  • File-based: Hashes, file names, paths
  • Network: IPs, domains, URLs, User-Agents
  • Registry: Keys created/modified
  • Behavior: Mutexes, named pipes, services
  • YARA rules: Reusable detection patterns

Common Evasion Techniques

  • Anti-VM/Sandbox: Detection of virtualized environments
  • Anti-Debugging: Techniques to evade analysis
  • Packing/Obfuscation: Code obfuscation
  • Process Injection: DLL injection, process hollowing
  • Rootkit Capabilities: Hiding of processes and files
  • Fileless Malware: Execution in memory only

MITRE ATT&CK Framework

Map the malware's behavior to MITRE ATT&CK techniques:

  • Initial Access (phishing, exploit public-facing app)
  • Execution (command and scripting, user execution)
  • Persistence (registry run keys, scheduled tasks)
  • Defense Evasion (obfuscation, process injection)
  • Command and Control (web protocols, DNS)
  • Exfiltration (exfiltration over C2, automated exfiltration)

Security Recommendations

  • [OK] Always analyze in an isolated (air-gapped) environment
  • [OK] Use VM snapshots for quick restoration
  • [OK] Document the entire analysis in detail
  • [OK] Share IOCs with the community (MISP, OTX)
  • [OK] Keep analysis tools always up to date
  • [OK] Create YARA rules for future detection
  • [OK] Integrate findings with threat intelligence platforms