Digital Forensics and Incident Response - A complete Guide

What is digital forensics and incident response?

Digital forensics and incident response are sub-disciplines of cyber security that are involved in investigating, identifying, remediating, and testifying cyber-attacks or incidents. DFIR is a combination of digital forensics and incident response which have two separate skill sets that set out to achieve a desirable outcome.

Digital forensics is an investigative branch of forensic sciences that collects and analyzes data and presents it in the form of digital evidence. It involves an understanding of what went wrong in the computer systems, networks, devices, laptops etc. These findings are then used in compliance regulations, litigations, or other related digital investigations.

Incident response, although similar to digital forensics, in collecting and analyzing digital data, it also responds to a security incident. It plays an important role in containment of the incident and recovery of the lost data.

Evolution of the DFIR process

In olden days too, the DFIR process, tools used, and methodology were all relatively similar if not same. What has changed are the goals, the advanced threats, and the technology used to address them. Earlier, the data collected was in the form of images from user’s computers, servers, log data etc. Once collected, they were then sent for analysis and further interpretation of the data using investigative tools. Computer experts then worked with the information obtained to weed out relevant and useful information.

Today too, the process is the same except for the fact that now more sophisticated tools such as EDR or XDR are in use, which allows hundreds or thousands of endpoints to rapidly access the data. This prompts immediate action from the responders as they can quickly understand what is happening, where it is happening, and what the threat actors are.

Challenges faced by digital forensics and incident response

With all the advantages that a DFIR offers, it comes with its share of challenges.

Digital forensics challenges are

• Scattered evidence - Digital evidence can be found among the various physical and virtual platforms which need a lot of expertise, tools, and resources to gather and investigate.
• Fast pace technology - Due to the evolving nature of various software programs and operating systems, forensic investigators must be well equipped to handle digital evidence in different versions and file formats.

Incident response challenges are

• Increased attack surface - Due to the vast attack surface of today’s computing systems, it becomes very difficult to get the correct overview of the network. It could result in user errors and run the risk of misconfiguration.
• Increased skill gap - There is a disproportionate ratio between the attacks that are occurring and the cyber security experts needed to address the attacks. A massive increase in data volume results in lack of sufficient expertise to handle the threat data. DFIR experts are few in number and are hired on retainer to facilitate the intervention required to tackle the threat crisis.

Best practices of DFIR

A powerful DFIR service will provide total peace of mind to businesses susceptible to attacks. DFIR service providers will ensure experts on the team with the latest know-how and the right DFIR tools.

Digital forensics relies its success totally on swift and thorough response. A rapid action taken within the stipulated time can prevent damage to data to a great extent. Accurately identifying the source of the attack, its scope, and impact will ensure prompt action and discovery of vulnerabilities to prevent future attacks.

Incident response ensures timely management of incidents without allowing it to escalate further. Accurate and reliable remedial measures will go a long way in reducing reputational loss, financial implications, and business downtime considerably. An ideal IR practice includes proper planning and implementation.

Together digital forensics and incident response form a formidable tool in bolstering the network and systems security posture and provide continuous support in the future too.

Steps of the DFIR process

The DFIR service is an amalgamation of two independent units, digital forensics and incident response, working together towards a single cause. Using threat intelligence delivered by the latest tools, techniques, and procedures by a team of experts ensures safety and security of all digital data and sensitive information.

Steps of the digital forensic process

Step 1 - Locate, and analyze all evidence of the digital media which is carried out by technical experts of the DFIR team.

Step 2 - After the data has been identified, isolate and preserve all the data till the end of the investigation. They may be required for compliance or litigation purposes.

Step 3 - Analyze and review the data to arrive at conclusions of the traces found.

Step 4 - Documentation of the reviewed data is essential for a thorough investigation and any future reference.

Step 5 - All evidence thus located, isolated, analyzed, reviewed, and preserved must be reported according to the necessary forensics protocol citing the analysis methodology and procedures.

Steps of the incident response process

Step 1 - Assess the scope of the incident, its severity and most important identify the indicators of compromise.

Step 2 - Conduct a thorough investigation using advanced systems and threat intelligence. This will help to detect threats, gather evidence, and provide in-depth information on the incident.

Step 3 - Although threats have been identified by this stage, the monitoring must continue to further alert to any security gaps or loopholes. This helps to eradicate any vulnerabilities found and address the problem areas.

Step 4 - All incidents identified must be reported individually with a plan for remedial measures.

Step 5 - Give a thorough briefing of the weak areas and the tactics and procedures to improve the security of the organization’s network and systems.

What capabilities are found in DFIR services?

The DFIR services are provided support via digital forensic technology solutions, as listed below:

• Acquires data from different sources, devices, endpoints, systems etc.
• Offers a wide overview and expansive visibility into the administrative processes and actions
• Provides comprehensive investigative capabilities that are complaint-friendly
• Provides feature-packed benefits such as powerful visualization while reporting
• Automates repetitive processes with less guesswork and more accuracy

What are the six steps of incident response?

Businesses big or small benefit hugely from the DFIR services. The six steps commonly found in incident response are:

1. Devise - Organizations prepare plans and put policies in place along with identifying incident managers and software platforms
2. Identify - IT managers are equipped to detect incidents, assess risk, scope and more.
3. Restrain - Managers work quickly to contain the threat to prevent its spread and further damage adjoining systems.
4. Remediate - Provide solutions to correct the issue. Resolve and remediate to ensure they don’t recur in the future.
5. Recover - Incident recovery is a big part in order to restore normalcy and continue operations. It also ensures continuous monitoring and reporting of the incident.
6. Communicate - Generate reports and communicate with stakeholders, consumers, and end-users in order to maintain transparency.

How does SOAR complement the DFIR process?

Security orchestration, automation, and response (SOAR) automatically identifies security incidents and responds to them. It is an extension of the DFIR role. Together they integrate with other cyber security tools such as firewalls and endpoint security to respond to complex security threats. SOAR augments and boosts the role of DFIR analysts by automating responses to incidents. It further works towards minimizing human errors in the DFIR process. SOAR uses predetermined playbooks to respond to incidents that are easily detected thereby reducing the workload of DFIR allowing them to focus on threat hunting, and other investigations that cannot be automated.

SOAR and DFIR work closely together to provide a robust security posture to an organization’s network and systems.

How to choose DFIR services?

Evaluate and choose a DFIR service by considering the following:

• Check the forensic capabilities of handling forensic evidence, usage of eDiscovery tools, evidence storage capability etc.
• Evaluate the qualifications and experience of the DFIR team employed by the DFIR service provider
• Check the track record of the DFIR provider for serving companies similar to your own in terms of industry and operations
• Verify the DFIR’s global presence and its location in multiple countries as on-site local presence may be required
• Check the services provided by the DFIR provider whether it is proactive or reactive. Proactive services will include threat hunting and vulnerability testing whereas reactive services will include incident response, attack investigation, and provide remedial measures
• Last but not least, compare pricing of various providers. Some may offer prepaid subscriptions where organizations do not use all consulting hours.

Frequently asked questions

1. How is digital forensics used in the incident response plan?

Digital forensics constitutes the following:

• File system forensics analyzes endpoints for indicators of compromise,
• Network forensics reviews network activity such as emails, web browsing, messaging etc. for potential attack sites,
• Log analysis reviews and interprets logs or data records for suspicious content
• Memory forensics analyzes the memory areas for threat or malicious attackers lurking in the file systems.

2. What questions are addressed by the DFIR process?

Digital forensics and incident response are related fields and a combination of the two are used to address questions such as:

• Who is the attacker?
• What is the impact of the attack/incident?
• How did the attacker enter the system?
• How was the operation escalated?
• How to ensure the attack is not repeated?
• What are the remedial measures to be taken to prevent recurrence of such incidents?

3. What is the value of DFIR?

A forensic post-mortem investigation into the attack gives valuable insights into the occurrence and the remedial measures to be taken. Any criminal activity usually leaves behind some form of evidence which can then be used to understand the situation. DFIR components include examination of the forensics evidence, an in-depth investigation, detailed analysis of the security events, response to breach and its recovery, preserving evidence for future use and analysis.

4. Who constitutes a DFIR team?

Incident response experts along with forensic examiners conduct the DFIR process. They work closely with the chief information security officer (CISO), privacy and security officers, legal teams, and SOC managers and analysts, and usually work from a security operations center (SOC).

5. What are the steps involved in an incident response lifecycle?

The National Institute of Standards and Technology (NIST) has instituted the following steps into an IR lifecycle.

1. Prepare a plan that would cover the detailed analysis of all incidents and allow for any changes if the need arises. The team should have a thorough understanding of the plan which should be regularly updated.

2. Gather all evidence and analyze them to take appropriate action. All forensic artifacts to be collected that will reveal traces of the event. Then a detailed analysis and report to be prepared that would indicate the timeline of the incident, root cause, possible intrusions, trail of the adversaries while in the system etc.

3. Once analysis is complete, containment of the threat, its complete eradication from the system, and recovery of the lost data come into focus. There should be permanent remediation of the threat so that it doesn’t recur.

4. A detailed post-mortem of the investigation to be done once it is complete, to learn from the past errors and take measures to close all the loopholes/gaps that may have thus been revealed. Retain any forensic evidence, if need be, for future reference.

Conclusion

A rapid escalation in cybersecurity attacks and the shift towards using cloud combined with remote working has brought in the need for a strategy with threat hunting capabilities. DFIR fits the bill perfectly. Digital forensics and incident response work hand-in-hand in dealing with cybercrimes.

In essence, digital forensics collects and investigates data to understand what transpired during the cyber-attack. Incident response further investigates, contains and recovers from a security incident. The tools, processes and procedures used by both digital forensics and incident responses are common. Together, they form a powerful tool in combating cyber-attacks effectively leading the way to thwart any future attacks successfully.

DFIR also aids in adhering to strict compliance standards set by the regulatory bodies and is useful in any litigation issues that may arise in the future.