Narrator: In this lesson,
we will learn about event response.
Event response includes the actions taken to handle,
investigate and mitigate a security incident
after it has been detected and contained.
Event response concepts include timeline reconstruction,
data recovery and extraction, and breach response.
Timeline reconstruction involves piecing together
the sequence of events leading up to
and during the incident.
Next, data recovery and extraction focus on restoring lost
or compromised data
and extracting critical information for analysis.
Finally, breach response encompasses the broader steps
of mitigating damage, securing systems,
and ensuring compliance with legal
and regulatory requirements.
Let's learn more about timeline reconstruction,
data recovery and extraction, and breach response.
First, we have timeline reconstruction.
Timeline reconstruction involves gathering data from logs,
system alerts, and other monitoring tools
to create a chronological account of events.
This timeline is crucial for identifying the attack path,
exploited vulnerabilities, and affected systems.
The National Institute of Standards and Technology,
or NIST, provides guidelines,
such as its special publication 800-61,
for establishing a comprehensive approach
to incident response, including timeline reconstruction.
Key tools for this process include security information
and event management, or SIEM systems,
which centralized log data from across the network
and forensic analysis tools,
like Autopsy or EnCase,
which assist in diving deeper into device level data
to track the attacker's movements.
In the timeline reconstruction process,
investigators carefully examine each event in the logs
to track when and how each component of the attack unfolded.
They look for specific patterns or anomalies in system
and firewall logs, such as unusual login times,
high frequency access to sensitive files,
or atypical use of administrative privileges.
Each data point is examined in sequence
to create a structured view of the attacker's actions.
However, attackers may attempt to manipulate logs
to obscure their trail, inserting false timestamps
or deleting specific entries.
So recognizing these manipulations is important
and often requires comparing logs across different systems
and devices, to identify gaps or inconsistencies.
For example, one way to detect a log manipulation,
is by correlating activity from various independent sources,
such as networking logs, application logs,
and even endpoint logs.
So if a critical action, like accessing a secured server,
appears in one log, but not in another
that typically records all access attempts,
this could indicate tampering.
Tools like Splunk and LogRhythm are invaluable here,
as they can automate comparisons and flag consistencies.
Analysts may also look for log gaps,
which are unexplained breaks in log entries
where no activity is recorded,
which could suggest log deletions.
So cross-referencing these logs with system alerts
and user behavior helps to reveal attempts
at log manipulation.
Second, we have data recovery and extraction.
Data recovery and extraction aim to restore compromised,
or lost data,
and to extract useful information for further analysis.
NIST's special publication 800-61,
the Computer Security Incident Handling guide,
and special publication 800-184,
the Guide for Cybersecurity Event Recovery,
as well as the Cybersecurity
and Infrastructure Security Agency, or CISA,
Incident Response and Recovery Playbook,
and the data backup options for cyber incident recovery,
offer protocols for effective data recovery and extraction,
ensuring that organizations
approach these processes systematically.
Additionally, tools like Disk Drill,
or Stellar Data Recovery allow teams
to recover data from damaged or encrypted drives.
And for more complex data extraction,
especially in cases involving mobile devices,
a tool called Cellebrite is commonly used.
In practice, data recovery starts by securing backup copies
of data before restoring from recent backups,
or decryption attempts.
Then the extraction of key incident data
involves isolating specific pieces of information
critical for understanding the breach,
such as compromised credentials or exfiltrated files.
This extraction also aids in refining forensic analysis,
giving investigators clear targets
to explore within the network.
Here the objective is not only to restore functionality,
but also to gather evidence
that can assist in identifying vulnerabilities.
For example, imagine a scenario where a breach leads
to the loss of critical files on a financial server.
By using a combination of backup recovery
and extraction tools,
the security team restores files from recent backups
and pulls key transaction data for further analysis.
They find that attackers accessed financial records
two days before the breach was detected, signaling a need
to upgrade monitoring systems.
Finally, the team documents each recovered file
and extracted item,
building an evidence trail that provides clarity
on what data was compromised
and where security gaps existed.
Third and last, we have breach response.
Breach response covers the critical steps taken
to mitigate damage, secure compromise systems,
and fulfill legal or regulatory obligations.
NIST special publication 800-61
and the ISO 27035,
Information Security Incident Management,
provide robust frameworks for breach response,
advising on measures like incident notification,
stakeholder communication, and system lockdown procedures.
In this effort, a core set of tools,
such as endpoint detection and response solutions,
like CrowdStrike or Carbon Black,
aid in identifying an isolating infected endpoints
to stop further spread.
Additionally, vulnerability scanners like Nessus,
help assess and mitigate weaknesses that allowed the breach.
So during a breach response, the security team acts swiftly
to contain and remove any traces of the attacker
from the network, working to secure systems
against future intrusions.
This includes identifying potentially compromised accounts,
ensuring secure backups and resetting credentials.
Throughout the breach response,
effective communication with stakeholders
and regulators is essential
and often required by data protection regulations,
such as GDPR or CCPA.
So by notifying affected parties,
organizations build transparency
and ensure compliance with legal standards,
which can reduce penalties and maintain trust.
For instance, after a healthcare breach,
a hospital security team may execute a breach response plan.
Here they isolate affected systems,
disable compromised accounts,
and conduct vulnerability scans
to determine the extent of the breach.
Then they notified patients
whose records may have been accessed and report the incident
to regulatory bodies within the required timeframe.
Following this response,
they implement stricter access controls
and update their incident response plan,
demonstrating a proactive commitment
to improving security and compliance.
So remember, event response involves
the coordinated actions taken to handle,
investigate, and mitigate a security incident
once it has been detected and contained.
Event response includes key concepts,
like timeline reconstruction, data recovery and extraction,
and breach response, each addressing different aspects
of managing the aftermath of a breach.
Timeline reconstruction is the process of gathering
and analyzing log data
to create a detailed sequence of events,
which helps identify exploited vulnerabilities
and the attacker's path.
Next, data recovery and extraction aim to restore lost
or compromise data,
and pull essential information for further analysis,
which is crucial for minimizing operational impact.
And finally, a breach response focuses on mitigating damage,
securing systems, and ensuring regulatory compliance,
minimizing the incident's impact on the organization
and upholding legal responsibilities.