A digital forensics and incident response (DFIR) investigator is a cybersecurity professional who uses investigative techniques and digital forensic tools to detect, respond to, and investigate cyber incidents and crimes. DFIR investigators have a critical role in an organization’s cybersecurity and risk management strategy. Their responsibilities include conducting digital forensic examinations, gathering and preserving evidence, determining the root cause and impact of incidents, and recommending ways to enhance defenses and prevent future attacks.
What does a DFIR investigator do?
The primary responsibilities of a DFIR investigator include:
Incident response
– Receiving and reviewing incident alerts from various security monitoring systems
– Conducting triage to determine the severity and scope of incidents
– Containing incidents to prevent further damage or data loss
– Recovering compromised systems and restoring business operations
– Identifying and mitigating vulnerabilities that were exploited
– Preserving evidence and documenting the incident response activities
Digital forensics
– Collecting digital evidence from compromised systems and storage media
– Performing forensic imaging to create immutable copies of evidence
– Analyzing images using forensic tools to uncover artifacts and events relating to the incident
– Reconstructing timelines of user and attacker activities
– Identifying indicators of compromise associated with the incident
– Recovering deleted or encrypted files when possible
– Documenting the findings in a forensic report
Threat hunting
– Proactively searching for anomalies and IOCs that could indicate an intrusion
– Pivoting on known threats or incidents to determine scope and impact
– Correlating information from multiple sources to detect sophisticated threats
– Identifying lateral movement of attackers within the network
– Discovering backdoors, compromised accounts, or persistence mechanisms
– Improving visibility into threats facing the organization
Malware analysis
– Performing static and dynamic analysis on suspicious files and malware samples
– Disassembling and reverse engineering malware to understand its capabilities
– Documenting indicators of compromise and tactical information to bolster defenses
– Developing and deploying custom signatures to detect malware
– Uncovering command and control infrastructure used by attackers
– Providing recommendations for preventing, detecting, and disrupting malware
What skills does a DFIR investigator need?
To be an effective DFIR investigator requires specialized technical skills and knowledge. Important capabilities include:
– Proficiency with digital forensics tools such as EnCase, FTK, Volatility, and forensics toolkits
– Knowledge of operating systems internals for Windows, Linux, and macOS environments
– Understanding of common attack techniques, malware, and cybersecurity concepts
– Network investigation skills such as packet analysis, network architecture, and protocols
– Programming or scripting skills to develop custom tools and automate tasks
– Knowledge of applicable laws and standards for evidence handling and investigations
– Project management and communication skills to coordinate IR activities and report findings
– Critical thinking, analysis, and problem solving skills
– Attention to detail and methodical evidence documentation practices
What are some typical DFIR tools?
DFIR investigators utilize a wide range of commercial, open source, and proprietary tools. Common tools include:
– Forensics software: EnCase, FTK, Autopsy, Sleuth Kit, Blacklight
– Malware analysis tools: IDA Pro, Ghidra, OllyDbg, Wireshark, INetSim
– Memory analysis tools: Volatility, Rekall, Redline
– Network analysis tools: Wireshark, tcpdump, NetworkMiner
– Host analysis tools: Sysinternals, Process Monitor, RegRipper
– Threat intelligence: VirusTotal, AbuseIPDB, ThreatConnect
– Scripting: Python, PowerShell, Bash, Perl
– Mobile forensics tools: Cellebrite, XRY, Oxygen Forensics
– E-discovery tools: Relativity, Nuix, LexisNexis Concordance
– Incident management: Jira, ServiceNow, SIEM platforms
DFIR investigators leverage both commercial forensic products as well as open source tools for examining diverse environments and use cases. They are constantly evaluating and learning new tools as technology evolves.
What training and certifications are available?
Some of the top training and certification options for aspiring DFIR investigators include:
– SANS FOR508: Advanced Incident Response and Threat Hunting
– SANS FOR572: Advanced Network Forensics and Analysis
– SANS FOR610: Reverse Engineering Malware
– GIAC Certified Forensic Analyst (GCFA)
– GIAC Certified Incident Handler (GCIH)
– GIAC Certified Reverse Engineering Malware (GREM)
– AccessData Certified Examiner (ACE)
– ISC2 Certified Cyber Forensics Professional (CCFP)
– EC-Council Computer Hacking Forensic Investigator (CHFI)
– IACIS Certified Forensic Computer Examiner (CFCE)
– CompTIA Cybersecurity Analyst (CySA+)
– EnCase Certified Examiner (EnCE)
Many colleges and universities now offer undergraduate and graduate programs in digital forensics as well. Ongoing hands-on training and experience responding to actual incidents is extremely valuable preparation for a DFIR career.
What is a typical DFIR workflow?
While each incident response engagement is unique, high-level phases of a typical DFIR investigation include:
Detection and notification
The process starts with the detection of a suspicious event or evidence of a breach. This may come from a variety of sources such as antivirus alerts, IDS warnings, user reports, or proactive threat hunting. The DFIR team is notified and begins coordinating the response.
Initiation and planning
The team holds initial meetings to review the known details and assigns roles and responsibilities. Response strategies are defined and an incident management plan created. Steps are taken to isolate and contain the incident.
Evidence collection and analysis
Now the “digital forensics” work starts. The team takes forensic images of affected systems and scrutinizes them for indicators of compromise and other artifacts. Potential malware is reverse engineered. Event logs and network traffic are reviewed.
Remediation
Based on the forensic findings, steps are taken to fully remove the attacker’s presence and harden security configurations. Compromised credentials are reset and backdoors are removed. Data may be restored from clean backups as warranted.
Reporting and lessons learned
A final report is authored detailing the incident overview, key events and findings, and remediation steps. Recommendations are made for enhancing security and preventing similar future attacks. Findings are shared internally and with law enforcement if appropriate.
What are some common DFIR team structures?
DFIR teams can be structured in several ways, depending on the size and needs of an organization. Some common models include:
– Dedicated internal team – Larger organizations often have a standing DFIR team on staff performing investigations, threat hunting, and preparing for incidents. Team sizes range from 2-3 analysts to over 25 for Fortune 500 companies.
– Shared pool model – Rather than dedicated DFIR specialists, organizations pull skilled responders from various IT and InfoSec groups as needed for each incident. This provides flexibility but less focus on continual readiness.
– External consultants – Many organizations outsource major incidents to third-party firms providing expert forensic analysis, legal services, public relations management, and overall response coordination.
– Managed services – Providers like Mandiant offer managed DFIR options combining technology, dedicated resources, and incident response-as-a-service capabilities.
– Law enforcement – Public agencies like the FBI and Secret Service have Their own forensic teams that work major cases by request. Most private sector responses don’t involve law enforcement.
There are tradeoffs with each approach, but mature cybersecurity programs incorporate skilled forensic capabilities in some fashion.
What legal issues are relevant for DFIR investigators?
DFIR teams must be knowledgeable of laws and regulations applicable to their geographies and industries. Some key legal considerations include:
– Licensing – Private investigators require licenses in some jurisdictions. DFIR professionals should know the requirements.
– Privacy laws – Laws like HIPAA and GDPR impose strict controls around personal data. Handling must comply with regulatory mandates and company policies.
– Legal holds – Digital evidence relating to litigation or an incident may need to be legally preserved in place via a hold notice.
– Chain of custody – Following strict procedures to track evidence handling and prevent tampering or alteration. Critical for preservation of evidence integrity.
– Law enforcement – Only certain serious incidents require reporting to law enforcement agencies. Most response activities occur independently.
– Data storage – Evidence and legal holds may necessitate retaining forensic images and documents far longer than normal data lifecycles.
Having in-house or outside counsel to advise on relevant statutes and case law is helpful for navigating thorny legal issues that often arise.
What is the future career outlook for DFIR professionals?
The job growth for DFIR experts is projected to be very strong. Cyberattacks are constant and evolving risks for businesses, creating enormous demand for incident response services. Some key trends include:
– The information security job market overall is growing much faster than other IT fields. Postings for IR/forensics roles in particular are rapidly increasing.
– As technology infrastructures grow more complex, companies need dedicated in-house specialists to investigate incidents. Outsourcing is becoming less feasible for large enterprises.
– DFIR teams are expanding beyond just reacting to embrace proactive threat hunting and vulnerability management – requiring more headcount.
– New regulations are also driving demand – such as Europe’s NIS2 directive mandating baseline cyber maturity including skilled forensic responders.
– Higher salaries and signing bonuses are being offered to attract and retain top IR/forensics talent – showing the skills shortage.
A profession at the leading edge of the cyber defense strategy for organizations, DFIR promises strong job prospects and an exciting, fast-paced career protecting critical assets and uncovering cyber threats.
Conclusion
Digital forensics and incident response is a niche discipline within cybersecurity focusing on the investigation and remediation of IT security incidents. DFIR investigators leverage highly technical forensic skills along with an investigative mindset to hunt threats, analyze malware, trace hacker activities, restore systems, and improve resilience. The field offers great career opportunities for technology professionals interested in this “digital detective” role safeguarding our data assets and infrastructure. With cyber risks continuing to expand, skilled DFIR experts will be in high demand well into the future.