Computer Forensics Basics

Computer Forensics Basics - Digital Detective Work

• Definition: Scientific process of identifying, preserving, analyzing, and presenting digital evidence from computers and related media, ensuring legal admissibility under BSA provisions.
• Core Goals:
  • Identify relevant digital evidence.
  • Preserve evidence integrity per BNSS requirements.
  • Analyze data to uncover facts.
  • Present findings clearly for BNS proceedings.
• Key Phases:
  • Identification: Define scope, locate potential evidence sources.
  • Preservation: Prevent data alteration. Use write-blockers, maintain BSA Section 63 compliance.
  • Acquisition: Create forensic images using specialized tools (e.g., EnCase, FTK, Autopsy, X-Ways).
  • Analysis: Examine data systematically.
  • Documentation: Detailed record per BNSS Section 172 requirements.
  • Presentation: Report findings objectively for court.
• Evidence Types: Volatile (RAM), Non-volatile (HDD, SSD), mobile devices, cloud data.

⭐ Chain of Custody: Documented chronological record of evidence handling (seizure, custody, control, transfer, analysis, disposition) as per BSA Section 45. Vital for legal admissibility.

Computer Forensics Basics - Bits & Bytes Trail

• Digital Evidence: Any information of probative value that is stored or transmitted in digital form, admissible under BSA provisions for electronic evidence.

• Data Types & Volatility:

  • Volatile Data:
    • Lost on power-off (RAM, cache, running processes, network connections, clipboard contents).
    • Highest collection priority. 📌 Order of Volatility: Capture ASAP per BNSS procedures.
  • Non-Volatile Data:
    • Persists without power (HDD, SSD, USB). SSD considerations: wear leveling, TRIM commands affect recovery.

• The Data Trail:

  • Storage Media: HDDs, SSDs, flash drives, optical discs, cloud storage, NAS.
  • File Systems: FAT, NTFS, exFAT, APFS, HFS+, ext4, XFS, Btrfs organize data; metadata (timestamps: MAC).
  • Data Remnants:
    • Unallocated Space: Deleted files may reside.
    • Slack Space: Between end-of-file & end-of-cluster.
    • Additional Sources: Hibernation files, temporary files, browser history, registry entries, system logs.

⭐ Even deleted files often leave recoverable traces in unallocated space or slack space, constituting valid evidence under BSA digital evidence standards.

Computer Forensics Basics - Cyber CSI Steps

• Preparation: Initial planning, tool gathering, legal authorization.
• Identification: Locating potential evidence (computers, drives, logs).
• Preservation: Preventing alteration of evidence; imaging drives (bit-stream copy).
  • Maintain Chain of Custody meticulously.
• Analysis: Examining data using forensic tools; timeline analysis, keyword searching.
  • Data recovery from deleted files/unallocated space.
• Documentation: Recording every step, finding, and conclusion.
• Presentation: Summarizing findings for legal or other proceedings; expert testimony.

⭐ Locard's Exchange Principle is fundamental: Every contact leaves a trace. This applies to digital interactions as well, forming the basis of digital evidence collection and analysis in cyber forensics investigations. (📌 Mnemonic: Locating Every Particle - LEP)

Computer Forensics Basics - Cyber Law Lens

• Information Technology (IT) Act, 2000: India's primary cyber law, now integrated with new criminal laws.
  • Framework for e-governance, cybercrimes under BNS and BNSS.
  • Key Sections:
    • Sec 43: Damage to computer systems.
    • Sec 65: Tampering with source code.
    • Sec 66: Hacking, data theft.
    • Sec 67: Publishing obscene material.
  • Cyber Appellate Tribunal for appeals under BNSS procedures.
• Bharatiya Sakshya Adhiniyam (BSA), 2023:
  • Electronic records admissibility provisions.
    • Certificate required for authenticity per landmark cases.
• Core Legal Tenets:
  • Chain of Custody: Documented evidence trail under BNSS.
  • Lawful Search & Seizure: Follow BNS and BNSS procedures.
  • Evidence Integrity: Ensuring unaltered evidence per BSA.

⭐ Electronic records provisions in BSA, 2023, reinforced by Anvar PV v. PK Basheer (2014) and Arjun Panditrao Khotkar cases, are pivotal for digital evidence admissibility in court.

High‑Yield Points - ⚡ Biggest Takeaways

• Computer forensics involves scientific examination of digital devices for legal evidence.
• Chain of custody is paramount for admissibility of digital evidence in court.
• Hashing algorithms (SHA-256, SHA-3) verify data integrity - MD5 deprecated for critical forensic verification due to collision vulnerabilities.
• Write blockers prevent accidental modification of original evidence during acquisition.
• Volatile data (e.g., RAM contents) is lost if not collected from a live system.
• Section 61 of Bharatiya Sakshya Adhiniyam, 2023 governs admissibility of electronic records.
• Steganography is the art of concealing data within other non-secret files.