What is forensic investigation in cyber security?

Forensic investigation in cyber security refers to the process of gathering, analyzing, and preserving digital evidence after a cyber attack or incident. It involves meticulously collecting and documenting data from compromised systems and networks to determine how an attack occurred, identify the attackers and their methods, assess the damage, and gather evidence to aid in prosecution. Forensic investigators use specialized tools and techniques to uncover clues and create a timeline of events surrounding a cybercrime.

Table of Contents

Why is forensic investigation important in cyber security?

Forensic investigation is a critical component of an effective cyber security program. Here are some of the key reasons why it matters:

Helps organizations understand how their systems were compromised and prevent future attacks using similar techniques.

Aids in identifying attackers, their motives, and their methods. This intelligence can be used to improve defenses.
Provides evidence to law enforcement to aid in prosecuting cyber criminals.
Helps quantify the damage and impact of an attack.

Allows organizations to notify customers, partners, and regulatory agencies as required in the event of a data breach.
Supports insurance claims and legal action after a cyber attack.
Fulfills compliance requirements around incident response and forensic investigations.

In summary, forensic investigation is crucial for learning from cyber attacks, improving security postures, catching attackers, recovering from incidents, and properly handling breaches.

What are the steps in a forensic investigation?

A forensic investigation generally involves the following key steps:

Planning and preparation – Develop incident response plans, acquire tools, and train staff on proper forensic procedures. Obtain authorization in advance for activities like system monitoring.

Detection and initial response – Detect the incident and perform initial triage to determine scope and impact. Isolate affected systems to prevent further damage.
Evidence collection – Identify, gather, and secure relevant evidence from compromised systems and networks. Follow strict chain of custody procedures.
Evidence analysis – Inspect and analyze the evidence to determine how the attack occurred, what was accessed or stolen, and who was responsible.

Damage and impact assessment – Assess effects of the incident and quantify the damage, data loss, recovery costs, and other impacts.
Reporting and presentation – Document findings in a report and present to key stakeholders. The report may be used internally or as evidence in legal proceedings.
Recovery and remediation – Use findings to remove malware, close security gaps, restore systems, and implement other measures to improve security.

Post-incident review – Review incident response and forensic procedures for improvements. Update policies, controls, and training as needed.

What types of evidence are collected in a forensic investigation?

Forensic investigators collect many types of digital evidence, including:

System and network logs – Logs from security tools like firewalls, intrusion detection systems, antivirus, etc. as well as operating system, application, and network device logs.

Network traffic captures – Copies of network traffic collected by SPAN ports, network taps, or tools like Wireshark.
Hard drive and storage data – Forensic disk images taken from affected systems using disk imaging tools.
Malware samples and artifacts – Malicious files, scripts, or forensic artifacts extracted from memory and storage.

Embedded device and IoT data – Data extracted from compromised embedded systems and Internet of Things devices.
Intrusion artifacts – Indicators of compromise like suspicious registry entries, installed programs, altered files, backdoors, and more.
Email data – Email messages and attachments related to phishing attacks, malware distribution, or communications with attackers.

Application and database data – Logs, transactions, changes, and dumps from affected databases and applications.
User activity information – Actions performed by users like commands executed or files accessed.
Authentication records – Records indicating access attempts, account logins and logouts.

What tools are used in forensic investigations?

Some of the key tools used by forensic investigators include:

Tool	Purpose
Disk imaging tools	Creating full forensic disk images, like EnCase or FTK Imager.
Live forensic tools	Collecting volatile data and artifacts from RAM on running systems, like Volatility.
Network forensic tools	Capturing and analyzing network traffic using Wireshark, tcpdump, NetworkMiner.
Forensic analysis suites	Comprehensive toolkits to extract artifacts from disk images, like EnCase or Autopsy.
Mobile forensic tools	Extracting and parsing data from mobile devices, like Oxygen Forensics.
Password cracking tools	Recovering lost or stolen credentials, like Hashcat or John the Ripper.
Reverse engineering tools	Disassembling and analyzing malware samples, like IDA Pro or Ghidra.
Registry analysis tools	Review Windows registry for signs of compromise, like RegRipper.
Log analysis tools	Aggregating and analyzing logs from multiple sources, like Splunk.
Scripting and automation	Automating repetitive analysis tasks with Python, PowerShell, etc.

What are some common challenges in forensic investigations?

Some of the most common challenges faced during cyber forensic investigations include:

Encrypted data makes evidence collection difficult without keys to decrypt.

Lack of logging or log rollover results in lack of historical data.
Anti-forensics techniques are used by attackers to cover their tracks.
Investigations can be very data and labor intensive, requiring lots of specialized skills and tools.

Legal restrictions can block access to certain data sources.
Cloud environments present jurisdictional and data access challenges for investigators.
IoT and embedded devices have limited data storage and volatility.

Sophisticated attacks exploit unknown or 0-day vulnerabilities.
Timeliness is key – digital evidence can be destroyed, tampered or lost if not preserved quickly.
High costs of forensic tools, hardware, training, and data storage.

What are some best practices for forensic investigations?

Some important best practices for conducting effective forensic investigations include:

Having clear incident response plans and procedures in place for evidence handling.
Using write-blockers and checksums to preserve integrity of original evidence.

Following strict chain of custody practices to prove evidence authenticity.
Documentation should be detailed, accurate and repeatable.
Promptly acquiring data from volatile memory and storage.

Storing evidence securely to prevent tampering or loss.
Having specialized forensic skills and staying up to date on tools and techniques.
Using standardized evidence collection and analysis methodologies.

Seeking legal guidance on evidence preservation, privacy and disclosure.
Using cryptography to protect confidentiality of sensitive evidence.
Being careful to draw conclusions only where evidence warrants.

What training and skills are required for forensic investigators?

Forensic investigators require a broad range of specialized skills and training, including:

Computer science and networking fundamentals.
In-depth knowledge of operating systems like Windows, Linux, and macOS.

Proficiency with security tools and technologies like firewalls, IDS, endpoints.
Ability to reverse engineer malware and analyze security artifacts.
Expertise in common forensic investigation tools and methodologies.

Data analysis and correlation capabilities.
Programming and automation skills for evidence gathering/analysis.
Knowledge of applicable laws and standards for evidence handling.

Understanding of anti-forensics techniques.
Writing and communication skills for formal investigative reporting.
Attention to detail and organization.

Ability to work under pressure and meet strict timelines.

Many forensic investigators have formal certifications like the SANS GIAC Certified Forensic Analyst (GCFA) or IACRB Certified Computer Forensics Examiner (CCFE). Ongoing professional education and training is crucial in this rapidly evolving field.

How long does a forensic investigation take?

The duration of a forensic investigation can vary widely depending on these factors:

Size and complexity of the environment – Large enterprise networks take longer than smaller networks.
Extent of the compromise – More systems affected means longer investigations.
Nature of the incident – Malware or data theft cases can be quicker than espionage.

Data volumes involved – The more data to collect and analyze, the longer it takes.
Legal requirements – Investigations involving legal action or prosecution take more time.
Availability of skilled personnel – Having more forensic experts speeds up investigations.

Use of automation – Automated evidence gathering and analysis accelerates investigations.
Cooperation from affected parties – Lack of cooperation can cause delays.

While every case is different, typical forensic investigations can range from weeks to months depending on these variables. Complex cases investigating nation-state attacks can span over a year.

How are forensic reports structured?

The forensic investigation report is the key output documenting the findings. While formats can vary, reports generally contain these sections:

Executive summary – High level overview of key findings.
Background – Context on the compromised environment and relevant history.

Timeline of events – Detailed chronology of the attack and incident response activities.
Analysis and evidence – In depth technical analysis of evidence and artifacts.
Malware analysis – Breakdown of malware purpose, capabilities and C2 infrastructure.

Findings and recommendations – Conclusions and remediation recommendations.
Appendices – Supporting data and evidence like logs and screenshots.

The report will have a chain of custody record detailing all evidence handling. Technical details may be explained for both technical and non-technical audiences.

What laws apply to forensic investigations?

Some key laws relating to cyber forensics include:

Fourth Amendment – Search and seizure protections limit evidence gathering.
Stored Communications Act – Governs obtaining stored electronic communications and records.

Electronic Communications Privacy Act – Requires warrants for real-time intercept of communications.
Computer Fraud and Abuse Act – Prohibits unauthorized access to computer systems and data.
HIPAA – Strict requirements for investigating breaches of protected health data.

Fed/State Privacy Laws – Requirements for handling personal data including notice, consent and disclosure.
Daubert Standard – Rules for experts presenting evidence as scientific testimony.
Data preservation laws – Require preserving data relevant for ongoing or imminent litigation.

Forensic investigators must adhere to these laws and ethical evidence collection practices. Legal counsel helps navigate any complex legal issues.

How is mobile device forensics different?

Mobile device forensics has some unique considerations:

Smaller data storage requires quick physical acquisition before data is lost.

Diverse mobile platforms require an array of forensic tools and procedures.
Encryption and authentication needs to be bypassed to extract data.
Critical evidence like app data, GPS history and message logs can be found on phones.

Manual manipulation of the device can alter key evidence on mobiles.
Over-the-air acquisition techniques allow remote evidence gathering from mobiles.
Investigators need detailed knowledge of various mobile OS internals.

Deleted data recovery is challenging on flash storage phones.
Cloud backups create jurisdictional and preservation challenges.

Mobile forensics needs trained examiners using validated tools and methods suitable for smartphones, tablets and IoT devices.

What trends are impacting forensic investigations?

Some emerging trends having an impact on cyber forensics include:

Growth in IoT, cloud and mobile expands the scope of investigations.
Distributed denial of service (DDoS) attacks overwhelm forensic resources.

Increasing use of anti-forensic tactics, encryption and obfuscation by attackers.
Ransomware and data wiper malware hinder evidence gathering and system recovery.
Shortage of qualified forensic experts is an industry-wide challenge.

Automation using ML and AI expedites evidence gathering, recovery and analysis.
Expanding legal requirements for breach notification and data protections.
Virtualization and container technologies create complexity for investigators.

Sharing threat intelligence improves indicators and aids faster investigations.

Forensic investigators must keep pace with legal, technological and threat trends to effectively gather digital evidence and track sophisticated adversaries across the expanding attack surface.

Conclusion

Forensic investigation enables decisive incident response through skilled evidence collection, analysis, and reporting. As cyber attacks grow in impact and frequency, organizations must invest in robust forensic capabilities encompassing personnel, tools, and procedures. Forensic investigators are the cyber crime scene investigators, piecing together clues that bring attackers to justice and provide lessons that improve future security. With persistent effort and creativity, the white hats can outpace black hat adversaries and bomb-makers. But it is a constant race against time, technology and human ingenuity where the stakes are always rising.