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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Incident response with AWS detective controls ⋆</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Dmytrii Tykholaz</string-name>
          <email>dmytrii.tykholaz.mkbbi.2023@lpnu.ua</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Roman Banakh</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Lesya Mychuda</string-name>
          <email>lesia.z.mychuda@lpnu.ua</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Andrian Piskozub</string-name>
          <email>andrian.z.piskozub@lpnu.ua</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Roman Kyrychok</string-name>
          <email>r.kyrychok@kubg.edu.ua</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Borys Grinchenko Kyiv Metropolitan University</institution>
          ,
          <addr-line>18/2 Bulvarno-Kudryavska str., 04053 Kyiv</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>CPITS-II 2024: Workshop on Cybersecurity Providing in Information and Telecommunication Systems II</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Lviv Polytechnic National University</institution>
          ,
          <addr-line>12 Stepana Bandery str., 79013 Lviv</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <fpage>190</fpage>
      <lpage>197</lpage>
      <abstract>
        <p>Loss of access to an Amazon Web Services (AWS) account can be caused by a variety of factors, ranging from human errors to hacks. Such incidents can have serious consequences for both companies and individuals, especially in the context of safeguarding critical data and ensuring business continuity. One of the most effective strategies for preventing AWS account loss is automating security configurations and incident response processes. Utilizing AWS Detective Controls tools in combination with deployment through Terraform addresses these challenges, enhancing security and resilience to potential attacks. The combined use of AWS Detective Controls and Terraform enables organizations to achieve enhanced security and efficiently respond to incidents. AWS Detective Controls acts as a constant monitoring environment, detecting potential threats and giving administrators the ability to quickly react to any incidents that could cause account loss. Terraform automates security configuration processes across the entire infrastructure, ensuring unified security rules for all AWS services. With such solutions, organizations can control their AWS accounts at a more advanced level, reducing the risk of account loss and ensuring protection against cyber threats. This is especially important in today's world, where cloud services play a key role in business processes and data protection. This topic is particularly relevant because securing information systems in cloud environments such as AWS presents a significant challenge for many companies. Research into investigating incidents using AWS Detective Controls helps improve awareness and establish new or improved approaches to detecting various security threats and swiftly responding to breaches. The results of such research will be useful for any organization using AWS, as well as for cybersecurity researchers, especially those working to improve the protection of cloud infrastructures.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;information security</kwd>
        <kwd>cybersecurity</kwd>
        <kwd>AWS</kwd>
        <kwd>account loss</kwd>
        <kwd>cybersecurity</kwd>
        <kwd>data protection</kwd>
        <kwd>incident response</kwd>
        <kwd>AWS Detective Controls</kwd>
        <kwd>Terraform</kwd>
        <kwd>security automation</kwd>
        <kwd>threat detection</kwd>
        <kwd>security-as-code</kwd>
        <kwd>cloud service provide</kwd>
        <kwd>DevSecOps</kwd>
        <kwd>cloud environment</kwd>
        <kwd>breaches 1</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        In developing this research, we built on both previous
studies and our own earlier work [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] in protecting cloud
infrastructure and access to it. In the research paper [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]
authors proposed a framework for enterprise cloud
infrastructure, while researchers in [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] focused on security
challenges using a “Security-as-Code” approach. In research
[
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] author discusses the impact of decoys involving
blockchain technologies on the state of information security
of the organization and the process of researching
cybercrime which is very important in cloud computing
environments as after gaining the access to account
attackers may launch computing resources for their benefit.
Often, to gain access to an account, attackers choose not to
attack the system directly but to gain access through the
weakest link—a person. In such cases, detecting the attack
is much more challenging since access to the resource often
looks legitimate [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ].
Leveraging insights from these studies, as well as our prior
research, we extended their methodologies to address
specific gaps in cloud infrastructure deployment and
security management, proposing solutions aimed at
enhancing security resilience by protecting cloud resources
and reducing the amount of misconfiguration that might
occur due to manual mistakes [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>
        For 2024 stolen credentials are the leading cause of data
breaches—16% of all incidents with data compromised,
contributing to a significant increase in intellectual property
theft, following the IBM Report: Escalating Data Breach
Disruption Pushes Costs to New Highs [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. These breaches
take an average of 10 months to detect and contain,
resulting in substantial financial losses.
      </p>
      <p>From 2023 to 2024, several major data breaches
occurred, including:</p>
      <p>Critical MOVEit vulnerability led to the compromise
of more than 2,300 organizations, including Shell,
British Airways, the US Department of Energy, and








</p>
      <p>
        Ontario’s government birth registry, BORN Ontario,
the latter of which led to the compromise of
information for 3.4 million people [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ].
      </p>
      <p>
        Boeing incident was assessing a claim made by the
Lockbit cybercrime gang that it had “a tremendous
amount” of sensitive data stolen from them [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ].
      </p>
      <p>
        AT&amp;T data-specific fields were contained in a data set
released in the dark [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ].
      </p>
      <p>
        Bank of America data breaches: a data breach
exposing the personally identifiable information (PII)
of 57,028 customers [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ].
      </p>
      <p>
        Data leaks often result from password theft, which
remains one of the most common causes of sensitive data
loss [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. A notable example is the data leak incident
involving stolen passwords that hackers used to access user
accounts. For example, Boeing’s stolen data was sold on the
dark web, giving other cybercriminals access to private
information and confidential stuff [
        <xref ref-type="bibr" rid="ref13 ref14">13, 14</xref>
        ].
      </p>
      <p>
        These cases demonstrate that losing access to social
media accounts typically results in privacy violations or loss
of control over personal information. However, losing
access to cloud computing accounts such as AWS can have
much more severe consequences. Attackers gaining access
to these accounts can not only steal critical data but also
alter infrastructure settings, potentially leading to
substantial financial losses, business damage, or even the
shutdown of critical operations [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ].
      </p>
      <p>While password loss can have serious consequences,
cloud computing accounts like AWS are particularly
vulnerable because they typically grant access to large
volumes of data and critical resources. This underscores the
importance of not only creating strong passwords but also
implementing multi-factor authentication and access
control systems to protect such accounts.</p>
      <sec id="sec-1-1">
        <title>1.1. Potential threats of AWS account loss</title>
        <p>Amazon Web Services (AWS) is one of the leading cloud
computing platforms today—thousands of companies use
AWS daily to store and process their data. However, there
is a risk of losing access to an AWS account, which could
lead to data breaches and severe security violations. Given
that AWS is a highly powerful and flexible platform offering
a wide range of services and infrastructure for data storage,
processing, and deployment of applications online
(including more than 200 services), the likelihood of such
incidents is quite significant.</p>
        <p>Various attack vectors can lead to the loss of an AWS
account. Potential threats include:</p>
        <sec id="sec-1-1-1">
          <title>Insufficient authentication and authorization. Use of weak passwords or poor password management.</title>
        </sec>
        <sec id="sec-1-1-2">
          <title>Phishing and spear-phishing attacks.</title>
        </sec>
        <sec id="sec-1-1-3">
          <title>Use of unsecured APIs.</title>
        </sec>
        <sec id="sec-1-1-4">
          <title>Inadequate network security. Weak authentication and authorization mechanisms.</title>
          <p>1.1.1. Insufficient authentication and</p>
          <p>authorization
Authentication and authorization are critical security
aspects in AWS. Insufficient authentication can allow an
attacker to gain access to an account and take malicious
actions. Insufficient authorization enables users to perform
unauthorized actions, potentially leading to severe
consequences.</p>
          <p>
            To prevent this, AWS’s best practices recommend using
multi-factor authentication (MFA) [
            <xref ref-type="bibr" rid="ref16">16</xref>
            ]. This requires not
only a password but also a code generated on a user’s
device. Additionally, AWS offers the use of authorization
policies to limit users’ access to resources and services. One
of the key services for managing access is Identity and
Access Management (IAM) [
            <xref ref-type="bibr" rid="ref17">17</xref>
            ]. AWS IAM allows for
managing individual users, user groups, and access rights to
various AWS account resources.
1.1.2. Use of weak passwords or poor password
management
Using weak passwords or improperly storing passwords is
also a serious security threat to AWS. If a password lacks
sufficient complexity or is stored in an insecure location, an
attacker can easily steal it and gain access to an account.
          </p>
          <p>To prevent this, AWS recommends using complex
passwords containing various symbols, numbers, and
lowercase letters. Furthermore, AWS advises using different
passwords for each service and storing them in a secure
location, such as a password manager.
1.1.3. Phishing attacks
Phishing and spear-phishing attacks are social engineering
techniques used to gain access to accounts. In the context of
AWS, attackers send emails or messages that appear to be
legitimate communications from AWS or another related
service. These messages may contain embedded links to
fake websites or malicious software that collects user
information.</p>
          <p>To avoid such situations, AWS advises users to be
cautious with emails and messages from unknown or
unverified sources. Additionally, AWS recommends using
protection technologies that can detect and block malicious
software and websites, such as antivirus and anti-phishing
tools.</p>
          <p>
            Inadequate data protection can also lead to the loss of
an AWS account. Attackers may gain access to user data
through various methods, including password and identity
theft. Specifically, attackers may use unsecured networks
and exploit software vulnerabilities to access data [
            <xref ref-type="bibr" rid="ref18 ref19 ref20">18-20</xref>
            ].
          </p>
          <p>
            To prevent this, AWS’s best practices recommend using
methods such as encryption, data loss prevention via
backups, and monitoring data access. Additionally, AWS
recommends using secure networks and reliable
communication channels for data transmission [
            <xref ref-type="bibr" rid="ref21">21</xref>
            ].
1.1.4. AWS denial of service
AWS may deny service to users who violate service
conditions or cause problems for other users. For instance,
AWS may suspend accounts involved in criminal activity or
spamming. Additionally, if a company or individual does
not pay for services, AWS may block the account.
          </p>
          <p>To prevent service denial, AWS encourages users to
adhere to service terms and avoid violating platform rules.
Additionally, AWS recommends regular payment of bills to
prevent account suspension.
1.1.5. Weak authentication and authorization
mechanisms
In some cases, AWS users do not adequately support the
security of their accounts. For example, users may fail to
regularly update software or improperly configure security
policies, which could lead to system security breaches and
account loss.</p>
          <p>AWS encourages users to regularly update software and
properly configure their security policies. Additionally,
AWS recommends using various security tools, such as
security monitoring, antivirus software, and data loss
prevention.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>2. Use of AWS detective controls for incident analysis</title>
      <p>Given the information in the previous section, it can be
concluded that the potential loss of access to an Amazon
Web Services (AWS) account can have serious
consequences for users, including loss of critical data,
significant financial recovery costs, and severe reputational
damage for businesses. To avoid such problems, users
should follow cybersecurity best practices and utilize tools
designed to protect AWS accounts.</p>
      <p>
        Some of the most important tools that ensure security
in AWS are detective controls [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ], such as CloudTrail [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ],
VPC Flow Logs [
        <xref ref-type="bibr" rid="ref24">24</xref>
        ], GuardDuty [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ], and Trusted Advisor
[
        <xref ref-type="bibr" rid="ref26">26</xref>
        ]. Each of these tools plays a crucial role in maintaining
system security.
      </p>
      <p>


</p>
      <p>CloudTrail allows users to track actions within their
accounts and log them. This helps identify suspicious
or unauthorized activities, which is a critical
component for preventing potential threats.</p>
      <p>VPC Flow Logs monitor network activity, helping
detect anomalies that may indicate security threats.
GuardDuty automatically identifies potential threats
and sends security incident alerts, allowing
administrators to quickly respond to threats.</p>
      <p>Trusted Advisor helps improve security, optimize
AWS service usage, and provides recommendations
for enhancing security practices.</p>
      <p>
        According to the AWS “Security Incident Response
Guide” [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ], organizations using AWS Detective Controls
generally reduce the time required to detect and respond to
security incidents. The introduction of additional services
allows for faster actions to mitigate threats compared to
companies not using these tools. Moreover, AWS provides
detailed analytics through tools such as AWS Security Hub,
which offers convenient reports on security status and
vulnerabilities, helping to promptly identify and resolve
issues. GuardDuty, in turn, detects unusual activity in the
account that could be a sign of possible breaches.
      </p>
      <p>Using these tools can significantly enhance AWS
account security, reduce the risk of data loss, and maintain
business process stability, making them essential
components of a modern cybersecurity strategy.</p>
      <p>
        According to a study by IBM, the cost of detecting and
eliminating cyberattacks increases by 13.7% annually on
average [
        <xref ref-type="bibr" rid="ref27">27</xref>
        ]. However, according to the same study, the use
of certain technologies and tools can reduce the cost of
eliminating the consequences of cyberattacks from 2.7% to
9.7%.
      </p>
      <p>One of the best practices for using these tools is to
regularly check CloudTrail and VPC Flow Logs to identify
potential security incidents and monitor network activity.
In addition, it is recommended that you set up automatic
subscriptions to Guard Duty notifications and regularly
check the recommendations from Trusted Advisor to ensure
optimal security for your account.</p>
      <p>In summary, AWS users should pay close attention to their
account security and utilize various tools and best practices
to protect their accounts. Among other things, detective
controls such as CloudTrail, VPC Flow Logs, Guard Duty,
and Trusted Advisor can help identify potential security
incidents and prevent their consequences.</p>
      <p>In addition, it is recommended that you pay attention to
setting up access to AWS resources, using multi-factor
authentication, regularly updating passwords, and using
data encryption.</p>
      <sec id="sec-2-1">
        <title>2.1. Incident response to account loss and access compromise</title>
        <p>Although the use of detective controls significantly reduces
the risk of losing access to an AWS account or being hacked,
such events can still happen. Therefore, it’s essential to have
a well-prepared incident response plan in place to minimize
the consequences and quickly regain control over the
account while protecting critical data and ensuring business
continuity.</p>
        <p>Accounts may be compromised for various reasons,
including data theft involving login credentials such as
usernames and passwords, often resulting from phishing
attacks, social engineering, or targeted password attacks.
Attackers may also attempt to access accounts by
compromising personal keys used for authentication. Stolen
or hacked keys can allow attackers to unauthorizedly log in
to systems, retrieve confidential information, or even make
dangerous changes to infrastructure or software.</p>
        <p>Such incidents can lead to significant security breaches,
risking confidential data leakage, disruption of critical
processes, and damage to reputations. Attackers can exploit
these vulnerabilities to alter system settings, modify
software, or even block access to essential resources. These
actions can result in major financial losses, penalties, a loss
of customer trust, and operational delays.</p>
        <p>To prevent such scenarios, it’s essential not only to
apply control mechanisms but also to have tools ready for a
swift incident response. This includes clearly defined steps
for identifying and isolating compromised accounts,
resetting passwords and keys, and restoring the system to a
stable state. Continuous employee training and the
implementation of multi-factor authentication also play a
key role in reducing risks.</p>
        <p>Thus, even with strong security measures like AWS
Detective Controls, having a comprehensive incident
response plan is critical for companies to react quickly to
threats, minimizing the negative impact on their operations.</p>
        <p>
          The first step [
          <xref ref-type="bibr" rid="ref28">28</xref>
          ] in responding to account loss or
access compromise is stopping the malicious activity. The
following actions should be taken to ensure security:



        </p>
        <p>Change the password or access key: In case of
suspicious activity on the account, it’s necessary to
immediately change the user’s password or access
key. After changing the password or key, all
configuration files that use the old password or key
should be updated.</p>
        <p>Disable the account: If there is suspicion that
attackers have access to the account, it’s critical to
disable the account immediately to prevent further
damage.</p>
        <p>
          Contact AWS Support: Upon detecting suspicious
activities, users should contact AWS Support and
report possible account loss or compromised security
[
          <xref ref-type="bibr" rid="ref29">29</xref>
          ].
        </p>
        <p>In response to account loss or compromised access to AWS
resources, Amazon Web Services provides an extensive set
of tools to ensure system security and protection. After such
an incident, it’s important to gather detailed information
about what occurred during a specific period across the
entire system. This information will help administrators
understand when and where the incident happened and
assess its impact on systems and security. Elements of
detective control can be used for a complete understanding
of the events.</p>
        <p>One of the most important tools is AWS CloudTrail,
which provides detailed logs of user and resource activity
within the AWS environment. The service stores activity
logs, such as logins, logouts, resource creation and deletion,
and data access. CloudTrail logs allow administrators to
detect unusual activity, as well as verify and analyze
potential security threats. With CloudTrail, you can track
who performed what actions in your systems, which helps
detect and investigate potential security incidents.</p>
        <p>The use of AWS Detective Controls tools can
significantly reduce the risk of account loss and
unauthorized access to AWS resources. They provide
automatic methods for configuring monitoring, auditing,
and responding to security events. This allows companies
and individual users to ensure maximum security for their
accounts and resources within the AWS environment.</p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Detective controls for incident analysis</title>
        <p>To prevent account loss in the AWS cloud platform and for
incident analysis, AWS offers various detective controls.
The detection tools provided by the AWS Cloud Platform
play an important role in preventing account loss and
analyzing security incidents. They help identify unusual or
suspicious account activity that may indicate a potential
security incident.</p>
        <p>The key detective controls offered by AWS include:



</p>
        <sec id="sec-2-2-1">
          <title>CloudTrail</title>
          <p>VPC Flow Logs
Amazon GuardDuty</p>
        </sec>
        <sec id="sec-2-2-2">
          <title>AWS Trusted Advisor.</title>
          <p>CloudTrail is an AWS-managed recording system that
provides a detailed audit of actions performed in an account.
The service logs all API calls, configuration changes, and
user interactions, thereby creating a detailed trace for
further analysis and reconstruction of the sequence of
events. CloudTrail logs are stored in highly available
Amazon S3 storage and can be analyzed using the AWS
Management Console or third-party data analysis tools.</p>
          <p>VPC Flow Logs is a service that records all network
activity that occurs in an Amazon Virtual Private Cloud
(VPC), such as incoming and outgoing packets over the
network. AWS provides various ways to view VPC Flow
Logs. Users can use the AWS VPC Flow Log Console or use
third-party tools to analyze and visualize the data.</p>
          <p>Amazon GuardDuty is a service that analyzes data from
various sources, including CloudTrail activity logs and VPC
Flow Logs, to identify potential security incidents. The
service uses machine learning algorithms to detect unusual
account activity, such as unauthorized access to account
resources or configuration changes.</p>
          <p>AWS Trusted Advisor is a service that provides
recommendations to users to optimize costs, ensure high
availability, and improve the security of their AWS
infrastructure environment. The service uses data from
users’ accounts and analyzes it to make recommendations
to optimize costs, ensure high availability, and improve the
security of its infrastructure environment. Trusted Advisor
offers several categories of recommendations, including
security, performance, cost, and availability.</p>
          <p>These controls allow administrators to detect potential
threats and incidents at an early stage and take the
necessary steps to prevent account loss and ensure the
security of the AWS environment.</p>
          <p>In addition to detecting threats and incidents, detective
controls also help users gain more detailed information
about these events. This can involve changing access
settings, performing additional security checks, and
collaborating with AWS Support for further investigation
and incident response. It’s important to note that detective
controls are part of a broader range of security tools
provided by AWS. By combining various tools and
following best security practices, organizations and
companies can enhance the security of their AWS
environments and protect their accounts and data.</p>
        </sec>
      </sec>
      <sec id="sec-2-3">
        <title>2.3. Using infrastructure as code to simplify the implementation of detective controls</title>
        <p>
          With the introduction of AWS cloud services, the use of
Infrastructure as Code (IaC), or automation tools such as
Terraform, is becoming increasingly popular [
          <xref ref-type="bibr" rid="ref30">30</xref>
          ]. These
tools allow users to manage and scale AWS infrastructure
using code [
          <xref ref-type="bibr" rid="ref31">31</xref>
          ].
        </p>
        <p>
          According to a 2021 analysis by Emergen Research, the
market size for infrastructure programming tools reached
$0.64 billion, and it is expected to grow at a compound
annual growth rate (CAGR) of 240% over the next ten years
[
          <xref ref-type="bibr" rid="ref32">32</xref>
          ]. Revenue is projected to grow from $0.64 billion in 2021
to $4.45 billion by 2030. The main driver of this growth is
the demand for better optimization of business operations,
necessitating new technological approaches as software
systems become increasingly complex and advanced.
        </p>
        <p>Terraform is a tool for automating the deployment of
computational infrastructure, which can be used to
automate the configuration and management of AWS
infrastructure. Terraform supports a wide range of
platforms, from major cloud providers like AWS, Azure, and
GCP, to smaller platforms such as Hetzner or 1&amp;1.
Additionally, it works with software such as Docker,
Kubernetes, and Chef, extending its functionality and
allowing users to work with these in tandem.</p>
        <p>Using Terraform, administrators can create and manage
various AWS services, establish security policies, and
respond to incidents quickly. One of the key benefits of
using Terraform for deploying and managing AWS services
is the ability to store the entire infrastructure in code. This
simplifies the replication and scaling of infrastructure while
ensuring security and preventing human errors.
Additionally, Terraform makes it easy to manage more
complex infrastructures, including networks, databases, and
other services. Tasks addressed with Terraform and other
infrastructure automation tools include reducing the risk of
human error, efficiently managing infrastructure
configuration, and minimizing the time required to
provision and scale infrastructure while ensuring
compliance with security and regulatory standards.
This and much more make Terraform a powerful tool for
managing infrastructure, both within a single hosting
platform and across multiple platforms simultaneously.</p>
        <p>In summary, the use of Terraform or other
infrastructure automation tools can help administrators
more efficiently and securely manage their company’s AWS
infrastructure, reduce deployment time, minimize errors,
and ensure compliance with security and regulatory
standards.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Security as code—overview</title>
      <p>Security as Code is a partially new approach that integrates
security practices into the software development lifecycle
by treating security configurations and policies as code.
This methodology enables teams to automate and version
control security measures alongside application code,
ensuring that security is built-in from the start rather than
tacked on later. By embedding security checks into
Continuous Integration/Continuous Deployment (CI/CD)
pipelines, organizations can proactively identify and
remediate vulnerabilities before they reach production. This
shift not only fosters a culture of security awareness among
developers but also aligns security objectives with business
goals, resulting in a more resilient and secure software
ecosystem.</p>
      <sec id="sec-3-1">
        <title>3.1. Advantages of security as code</title>
        <p>One of the primary advantages of Security as Code is the
enhancement of overall security posture through automation.
By automating security checks, organizations can reduce the
risk of human error and ensure consistent enforcement of
security policies across all environments. Additionally, this
approach enables faster feedback loops, allowing developers
to detect and address vulnerabilities early in the development
process, thereby minimizing costly post-release fixes.
Furthermore, version control for security configurations
facilitates easier auditing and compliance, as teams can track
changes and maintain a clear history of security measures.
Ultimately, Security as Code promotes collaboration between
development and security teams, fostering a more agile and
efficient approach to software development while
significantly improving security outcomes.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Disadvantages of security as code</title>
        <p>Despite its benefits, Security as Code also presents
challenges. One significant disadvantage is the potential for
over-reliance on automation, which can lead to
complacency among teams. If security checks are
automated without proper oversight, critical vulnerabilities
may go unnoticed, resulting in security gaps. Additionally,
implementing Security as Code requires a cultural shift and
the acquisition of new skills, which can be daunting for
some organizations. The initial setup of automated security
tools can also be resource-intensive, requiring time and
investment that may not yield immediate returns.
Moreover, integrating these practices into existing
workflows may introduce complexity, making it essential to
carefully manage the transition to ensure it doesn’t disrupt
development processes.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Difference between manual and automated configuration</title>
        <p>Manual configuration involves human intervention to set
security policies and controls, which can be time-consuming
and prone to human error. Each configuration change requires
individual attention, leading to inconsistencies and potential
security risks if best practices are not consistently applied. On
the other hand, automated configuration employs tools and
scripts to enforce security policies systematically and
consistently. This approach reduces the likelihood of human
error, enhances speed and efficiency, and allows for scalability
in managing security across large environments. While manual
configuration can offer flexibility in unique scenarios,
automated configuration ensures a more uniform and reliable
implementation of security measures, critical for maintaining a
strong security posture in rapidly evolving software
development landscapes.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Automating the configuration of</title>
      <p>some detective controls with</p>
    </sec>
    <sec id="sec-5">
      <title>Terraform</title>
      <p>As we mentioned earlier, manually configuring these
services is not a complicated process, the use of
softwarebased configuration using Terraform is becoming more
common due to the need for flexibility and re-deployment
capabilities. The code samples provided below provide the
basic structure for the setup of each detective control
mentioned in this research with a brief explanation of each
step and configuration.</p>
      <sec id="sec-5-1">
        <title>4.1. Using infrastructure as code to set up AWS GuardDuty</title>
        <p>resource "aws_guardduty_detector" "_" {
enable = true
}
resource "aws_guardduty_organization_admin_account"
"account_id" {
admin_account_id = "123456789012"
}
resource "aws_guardduty_invite_accepter" "detector" {
detector_id = aws_guardduty_detector._.id
master_account_id
aws_guardduty_detector.primary.account_id
}
resource
"example" {
auto_enable_organization_members = "ALL"
detector_id = aws_guardduty_detector._.id
datasources {
s3_logs {
auto_enable = true
"aws_guardduty_organization_configuration"
=
}
kubernetes {
audit_logs {
enable = true
}
}
malware_protection {
scan_ec2_instance_with_findings {
ebs_volumes {
auto_enable = true
}
}
}
}
}
resource "aws_guardduty_detector" "_" {
provider = aws._
}
This GuardDuty configuration enables comprehensive
threat detection across an AWS organization.</p>
        <p>The aws_guardduty_detector resource activates
GuardDuty for the entire organization, allowing it to
monitor and detect potential security threats.</p>
        <p>To streamline the process, the
aws_guardduty_invite_accepter automatically accepts
GuardDuty invitations for member accounts, ensuring
centralized control over the organization’s security.</p>
        <p>The configuration part ensures that GuardDuty is
automatically enabled for all current and future
organization members, while also enabling advanced data
source monitoring. This includes automatic logging for S3
access, Kubernetes audit logs for tracking resource access
and changes, and malware protection scans on EC2
instances, particularly focusing on EBS volumes. Finally, a
secondary aws_guardduty_detector resource configures
another detector for use by the primary account for full
security coverage.</p>
      </sec>
      <sec id="sec-5-2">
        <title>4.2. Using infrastructure as code to set up AWS cloud trail</title>
        <p>resource "aws_s3_bucket" "_" {
bucket = "cloudtrail-bucket"
versioning {
enabled = true
}
}
resource "aws_cloudtrail" "CT" {
name = "test-cloudtrail"
s3_bucket_name = aws_s3_bucket._.bucket
include_global_service_events = true
is_multi_region_trail = true
event_selector {
read_write_type = "All"
include_management_events = true
data_resource {
type = "AWS::S3::Object"
values = ["arn:aws:s3:::cloudtrail-bucket/*"]
}
}
}</p>
        <p>This CloudTrail configuration sets up comprehensive
logging for AWS account activities. The aws_s3_bucket
resource creates an S3 bucket named “cloudtrail-bucket”,
which is used to store CloudTrail logs, with versioning
enabled to protect log integrity.</p>
        <p>The aws_cloudtrail resource establishes a CloudTrail
named “test-cloudtrail” that logs all API activity and events
across AWS services. It includes global service events,
making it a multi-region trail that captures actions in all
AWS regions.</p>
        <p>An event_selector is configured to log all read and write
operations, and it ensures that management events, such as
account-level changes, are captured.</p>
        <p>The configuration also specifies that all S3 object-level
activity within the “cloudtrail-bucket” is logged, ensuring
detailed audit trails for S3 operations.</p>
      </sec>
      <sec id="sec-5-3">
        <title>4.3. Using infrastructure as code to set up VPC flow logs</title>
        <p># Create VPC
resource "aws_vpc" "test_vpc" {
cidr_block = "10.0.0.0/16"
}
}
}
{
# Attach necessary policies to the IAM role
resource "aws_iam_role_policy_attachment" "_" {
role = aws_iam_role.test_flow_log_role.name
policy_arn =
"arn:aws:iam::aws:policy/servicerole/AmazonVPCFullAccess"
}</p>
        <p>This VPC Flow Logs configuration is designed to
capture and monitor network traffic within a defined
Virtual Private Cloud (VPC) environment. The aws_vpc
resource creates a VPC with a CIDR block of 10.0.0.0/16,
which sets up the network’s IP address range and provides
an isolated section within the AWS infrastructure for
deploying resources. Within this VPC, the aws_subnet
resource provisions a subnet, defining a smaller CIDR block
of 10.0.1.0/24 within the VPC’s range, and placing it in the
availability zone us-west-1a for high availability and
redundancy.</p>
        <p>The aws_flow_log resource is used to enable VPC Flow
Logs, which captures all network traffic
(traffic_type = "ALL") both to and from resources within the
VPC and subnet. The logs are sent to a specified
CloudWatch log group
(arn:aws:logs:us-west1:123456789012:log-group:/aws/vpc/flow-logs), allowing for
real-time monitoring and analysis of network traffic. This is
crucial for security, troubleshooting, and compliance
purposes, as it allows the tracking of all VPC activity,
including incoming and outgoing data.</p>
        <p>To facilitate the logging, an IAM role is created with
aws_iam_role, named “test-flow-log-role”, which includes
an assume-role policy allowing the VPC Flow Logs service
to take on this role. The policy grants the necessary
permissions for the VPC Flow Logs service to write log data
into CloudWatch. Finally, the aws_iam_role_policy_
attachment attaches the AmazonVPCFullAccess policy to
the IAM role, providing full permissions over VPC resources
and flow log management. This ensures that the role can
manage and interact with the flow of log resources
effectively while allowing logs to be securely stored and
accessed for further analysis.</p>
      </sec>
      <sec id="sec-5-4">
        <title>4.4. Using infrastructure as code to set up AWS trusted advisor</title>
        <p>#Trusted Advisor
# Enable Trusted Advisor checks
resource "aws_trusted_advisor_check_refresh_status"
"example" {
check_ids = [
"eW7HH0l5z0" # Replace with the check IDs you want to
enable
]
}</p>
        <p>This Trusted Advisor configuration automates the
process of enabling, refreshing, and monitoring AWS
Trusted Advisor checks. The
aws_trusted_advisor_check_refresh_status resource ensures that
specific Trusted Advisor checks, identified by their
check_ids (in this case, “eW7HH0l5z0”), are refreshed
regularly to provide up-to-date insights on the health and
best practices of the AWS environment. Trusted Advisor
checks cover key areas like cost optimization, performance,
security, and fault tolerance, making it essential to have the
latest data available.</p>
        <p>To facilitate real-time notifications, the aws_sns_topic
resource creates an SNS (Simple Notification Service) topic,
named “trusted-advisor-notifications”, which is used to
broadcast alerts or updates related to Trusted Advisor
checks. This ensures that any critical issues or
improvements recommended by the Trusted Advisor can
trigger immediate notifications to the relevant stakeholders.</p>
        <p>The aws_trusted_advisor_check resource configures a
specific check (check_id = "eW7HH0l5z0") and ties it to the
previously created SNS topic. By linking the check with
SNS, any changes in the status of this Trusted Advisor check
will automatically trigger notifications, keeping the team
informed of critical findings in real-time.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>5. Conclusions</title>
      <p>This study focused on the use of key AWS security tools:
CloudTrail, VPC Flow Logs, GuardDuty, and Trusted
Advisor. Each of these tools provides specific security
controls to monitor and prevent unauthorized access to
AWS infrastructure.</p>
      <p>While manual configuration allows us to quickly access
AWS Detective Controls services, it requires significant
manual effort and maintaining consistency across
environments. Instead, infrastructure as code using
Terraform provides a repeatable and scalable configuration
of AWS Detective Controls. This approach simplifies the
configuration and management of AWS services with a
convenient, easy-to-understand configuration file format
that is stored in a repository.</p>
      <p>The main objective of the study was to examine in detail
the capabilities of AWS Detective Controls to detect and
prevent security threats in cloud environments. To
effectively deploy and manage these mechanisms, we used
Infrastructure as a Code (IaC) with Terraform. Thanks to
Terraform modules, we achieved a stable and auditable
AWS Detective Controls configuration, which allowed us to
focus on analyzing and optimizing threat detection rules.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>D.</given-names>
            <surname>Tykholaz</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.</given-names>
            <surname>Banakh</surname>
          </string-name>
          ,
          <article-title>Account Protection in AWS with Detective Controls</article-title>
          , in: International Scientific and Technical
          <string-name>
            <surname>Conference</surname>
          </string-name>
          (
          <year>2023</year>
          )
          <fpage>95</fpage>
          -
          <lpage>96</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <given-names>V.</given-names>
            <surname>Khoma</surname>
          </string-name>
          , et al.,
          <article-title>Comprehensive Approach for Developing an Enterprise Cloud Infrastructure</article-title>
          ,
          <source>in: Cybersecurity Providing in Information and Telecommunication Systems</source>
          , vol.
          <volume>3654</volume>
          (
          <year>2024</year>
          )
          <fpage>201</fpage>
          -
          <lpage>215</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>O.</given-names>
            <surname>Vakhula</surname>
          </string-name>
          ,
          <string-name>
            <given-names>I.</given-names>
            <surname>Opirskyy</surname>
          </string-name>
          ,
          <string-name>
            <surname>O. Mykhaylova,</surname>
          </string-name>
          <article-title>Research on Security Challenges in Cloud Environments and Solutions based on the “Security-as-Code” Approach, in: Cybersecurity Providing in Information and Telecommunication Systems II</article-title>
          , vol.
          <volume>3550</volume>
          (
          <year>2023</year>
          )
          <fpage>55</fpage>
          -
          <lpage>69</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>S.</given-names>
            <surname>Vasylyshyn</surname>
          </string-name>
          , et al.,
          <article-title>A model of decoy system based on dynamic attributes for cybercrime investigation</article-title>
          ,
          <source>Eastern-European J. Enterprise Technol</source>
          .
          <volume>1</volume>
          (
          <issue>9</issue>
          (
          <issue>121</issue>
          ) (
          <year>2023</year>
          )
          <fpage>6</fpage>
          -
          <lpage>20</lpage>
          . doi:
          <volume>10</volume>
          .15587/
          <fpage>1729</fpage>
          -
          <lpage>4061</lpage>
          .
          <year>2023</year>
          .
          <volume>273363</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>S.</given-names>
            <surname>Yevseiev</surname>
          </string-name>
          , et al.,
          <article-title>Models of socio-cyber-physical systems security</article-title>
          ,
          <source>Kharkiv: РС ТЕСHNOLOGY СЕNTЕR</source>
          ,
          <volume>184</volume>
          (
          <year>2023</year>
          ). doi:
          <volume>10</volume>
          .15587/
          <fpage>978</fpage>
          -617-7319-72-5.
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          <article-title>[6] Most enterprises highly vulnerable to security events caused by cloud misconfiguration</article-title>
          . URL: https://www.helpnetsecurity.com/
          <year>2018</year>
          /10/05/cloudmisconfiguration/
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>IBM</given-names>
            <surname>Report</surname>
          </string-name>
          <article-title>: Escalating Data Breach Disruption Pushes Costs to New Highs</article-title>
          . URL: https://newsroom.ibm.com/2024-07-30
          <article-title>-ibm-reportescalating-data-breach-disruption-pushes-costs-tonew-highs</article-title>
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          <article-title>[8] Critical MOVEit vulnerability puts huge swaths of the Internet at severe risk</article-title>
          . URL: https://arstechnica.com/ security/2024/06/critical-moveit
          <article-title>-vulnerability-putshuge-swaths-of-the-internet-at-severe-risk/</article-title>
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          <article-title>[9] Boeing says “cyber incident” hit parts business after ransom threat URL: https://www.reuters.com/ business/aerospace-defense/boeing-investigatingcyber-incident-affecting-parts-</article-title>
          <string-name>
            <surname>business-</surname>
          </string-name>
          2023-11-01/
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [10] AT&amp;
          <string-name>
            <surname>T Addresses Recent</surname>
          </string-name>
          <article-title>Data Set Released on the Dark Web</article-title>
          . URL: https://about.att.com/story/2024/ addressing
          <article-title>-data-set-released-on-dark-web</article-title>
          .html
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [11]
          <article-title>Bank of America 2024 Data Breach and Third Party Risk</article-title>
          . URL: https://panorays.com/blog/boa-databreach-2024/
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          [12]
          <string-name>
            <surname>Verizon</surname>
          </string-name>
          <article-title>'s 2024 Data Breach Investigations Report (DBIR)</article-title>
          . URL: https://www.verizon.com/business/ resources/reports/dbir/2024/summary-of-findings/
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [13]
          <string-name>
            <given-names>Y.</given-names>
            <surname>Dreis</surname>
          </string-name>
          , et al.,
          <article-title>Model to Formation Data Base of Internal Parameters for Assessing the Status of the State Secret Protection</article-title>
          ,
          <source>in: Workshop on Cybersecurity Providing in Information and Telecommunication Systems, CPITS</source>
          , vol.
          <volume>3654</volume>
          (
          <year>2024</year>
          )
          <fpage>277</fpage>
          -
          <lpage>289</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [14]
          <string-name>
            <given-names>P.</given-names>
            <surname>Anakhov</surname>
          </string-name>
          , et al.,
          <article-title>Protecting Objects of Critical Information Infrastructure from Wartime Cyber Attacks by Decentralizing the Telecommunications Network</article-title>
          ,
          <source>in: Workshop on Cybersecurity Providing in Information and Telecommunication Systems</source>
          , vol.
          <volume>3050</volume>
          (
          <year>2023</year>
          )
          <fpage>240</fpage>
          -
          <lpage>245</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          [15]
          <string-name>
            <given-names>A.</given-names>
            <surname>Zahynei</surname>
          </string-name>
          , et al.,
          <article-title>Method for Calculating the Residual Resource of Fog Node Elements of Distributed Information Systems of Critical Infrastructure Facilities</article-title>
          ,
          <source>in: Workshop on Cybersecurity Providing in Information and Telecommunication Systems, CPITS</source>
          , vol.
          <volume>3654</volume>
          (
          <year>2024</year>
          )
          <fpage>432</fpage>
          -
          <lpage>439</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          [16]
          <string-name>
            <surname>Multi-Factor Authentication</surname>
          </string-name>
          (
          <article-title>MFA) for IAM</article-title>
          . URL: https://aws.amazon.com/iam/features/mfa/
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          [17]
          <article-title>IAM</article-title>
          . URL: https://aws.amazon.com/iam/?nc=bc&amp; pg=f-mfa
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          [18]
          <string-name>
            <given-names>P.</given-names>
            <surname>Anakhov</surname>
          </string-name>
          , et al.,
          <article-title>Evaluation Method of the Physical Compatibility of Equipment in a Hybrid Information Transmission Network</article-title>
          ,
          <source>Journal of Theoretical and Applied Information Technology</source>
          <volume>100</volume>
          (
          <issue>22</issue>
          ) (
          <year>2022</year>
          )
          <fpage>6635</fpage>
          -
          <lpage>6644</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          [19]
          <string-name>
            <given-names>V.</given-names>
            <surname>Zhebka</surname>
          </string-name>
          , et al.,
          <article-title>Optimization of Machine Learning Method to Improve the Management Efficiency of Heterogeneous Telecommunication Network</article-title>
          ,
          <source>in: Workshop on Cybersecurity Providing in Information and Telecommunication Systems</source>
          , vol.
          <volume>3288</volume>
          (
          <year>2022</year>
          )
          <fpage>149</fpage>
          -
          <lpage>155</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          [20]
          <string-name>
            <given-names>V.</given-names>
            <surname>Zhebka</surname>
          </string-name>
          , et al.,
          <source>Stability Method of Connectivity Automated Calculation for Heterogeneous Telecommunication Network, in: Workshop on Cybersecurity Providing in Information and Telecommunication Systems</source>
          , vol.
          <volume>3188</volume>
          (
          <year>2021</year>
          )
          <fpage>282</fpage>
          -
          <lpage>287</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation>
          [21]
          <string-name>
            <surname>Routavaara</surname>
          </string-name>
          ,
          <article-title>Security monitoring in AWS public cloud</article-title>
          ,
          <source>Bachelor's Thesis</source>
          , Technology Information and Communication
          <string-name>
            <surname>Technology</surname>
          </string-name>
          (
          <year>2020</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation>
          [22]
          <article-title>Detective controls</article-title>
          . URL: https://docs.aws.amazon. com/prescriptive-guidance/latest/aws-securitycontrols/detective-controls.html
        </mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation>
          [23]
          <article-title>CloudTrail</article-title>
          . URL: https://aws.amazon.com/cloudtrail/ ?nc1=h_ls
        </mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation>
          [24]
          <string-name>
            <given-names>VPC</given-names>
            <surname>Flow</surname>
          </string-name>
          <article-title>Logs - Log and View Network Traffic Flows</article-title>
          . URL: https://aws.amazon.com/blogs/aws/vpcflow-logs
          <article-title>-log-and-view-network-traffic-flows/</article-title>
        </mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation>
          [25]
          <string-name>
            <given-names>Guard</given-names>
            <surname>Duty</surname>
          </string-name>
          . URL: https://www.amazonaws.cn/en/ guardduty/
        </mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation>
          [26]
          <string-name>
            <given-names>Trusted</given-names>
            <surname>Advisor</surname>
          </string-name>
          . URL: https://docs.aws.amazon.com/ awssupport/latest/user/trusted-advisor.html
        </mixed-citation>
      </ref>
      <ref id="ref27">
        <mixed-citation>
          [27]
          <article-title>IBM Cost of data breaches 2022</article-title>
          . URL: https://www.ibm.com/reports/data-breach
        </mixed-citation>
      </ref>
      <ref id="ref28">
        <mixed-citation>
          [28]
          <string-name>
            <given-names>AWS</given-names>
            <surname>Security Incident</surname>
          </string-name>
          <article-title>Response</article-title>
          . URL: https://docs.aws.amazon.com/whitepapers/latest/aws -security
          <article-title>-incident-response-guide/aws-securityincident-response-guide</article-title>
          .html
        </mixed-citation>
      </ref>
      <ref id="ref29">
        <mixed-citation>
          [29]
          <string-name>
            <given-names>AWS</given-names>
            <surname>Support</surname>
          </string-name>
          . URL: https://console.aws.amazon.com/ support/home/?nc2=h_ql_cu
        </mixed-citation>
      </ref>
      <ref id="ref30">
        <mixed-citation>
          [30]
          <string-name>
            <surname>Terraform</surname>
          </string-name>
          . URL: https://www.terraform.io/
        </mixed-citation>
      </ref>
      <ref id="ref31">
        <mixed-citation>
          [31]
          <article-title>Terraform usage</article-title>
          . URL: https://enlyft.com/tech/ products/hashicorp-terraform
        </mixed-citation>
      </ref>
      <ref id="ref32">
        <mixed-citation>
          [32]
          <article-title>Infrastructure as Code Market Size to Reach USD 4</article-title>
          .45 Billion in 2030 | Emergen Research. URL: https://www.prnewswire.com/newsreleases/infrastructure-as
          <article-title>-code-market-size-to-reachusd-4-45-billion-</article-title>
          <string-name>
            <surname>in-</surname>
          </string-name>
          2030
          <string-name>
            <surname>--</surname>
          </string-name>
          emergen-research301737553.html
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>