What is HIDS? A Deep Dive into Host Based Intrusion Detection Systems

Both individuals and enterprises face persistent threats from cyber attacks and constantly evolving Buffer Overflow Attacks and persistent attacks. Attackers are always looking for new techniques to breach systems and with the ever-changing cyber environment, organizations have to depend on a range of security methods. One of the most precise tools for cybersecurity is Host-Based Intrusion Detection Systems, HIDS.

In this blog, we comprehensively explore HIDS,  from its definition, its working, various types, to integrating its features with other Intrusion Detection Systems like NIDS. Also, we would look into the need and tools required, best practices to deploy HIDS software, and the security policies on protecting HIDS.  

HIDS Definition: What is Host Based Intrusion Detection Systems?  

It is a type of Intrusion Detection System that looks into and inspects a host system for anomalies: a computing system and to device its packets. A Host Based Intrusion Detection System works on dedicated devices called hosts, like servers, desktops and laptops.

The purpose of a HIDS is to identify threats by reviewing log files, system calls, application behavior, file system changes, and more. Essentially, HIDS functions like a digital watchdog that notifies system admins of any strange or possibly harmful activities.

Why HIDS Matters in Modern Cybersecurity?

In Network Cybersecurity, intrusions can mostly be detected from a network perimeter or boundary. As we have more layered, hidden, and internal attacks, or attacks that don’t trigger any strange network behavior, internal or network-based systems can prove ineffective. This is where HIDS comes into play. Host-based Intrusion Detection Systems (HIDS) allow for visibility, which is critical in the detection of insider threats, harmful software, and other alterations that indicate a breach.

HIDS vs NIDS: Key Differences

Benefits of HIDS Security

Early Detection of System-Level Threats

HIDS is useful for an organization’s security posture because the system aids in the identification of threats that have bypassed the initial network defenses or stem from a host that has been compromised. HIDS is not like network-based systems that only analyze traffic flows, because it watches the action of the host. Because HIDS watches the actions of the host, it is able to detect troubling events such as the execution of abnormal processes, resource access by unauthorized entities, and access patterns that significantly deviate from the baseline in real-time to minimize an attacker’s time to exploit the system.

This capability is critical because sophisticated perimeter defenses are susceptible to being bypassed. After an attacker breaches a system, HIDS provides critical insight into malicious activities within the system, acting with precise visibility into the after-breach actions. HIDS system monitoring allows security teams to flag, notify, and respond to threats swiftly, isolating critical systems, and containing threats before they spread across the network or exfiltrate sensitive data. This form of early detection and system monitoring substantially minimizes the impact of a cyberattack.  

Greater Insight Into Host-Specific Activity  

An obvious benefit of HIDS is having a more detailed understanding of activities for a particular host. HIDS focuses on the precise processes being executed on a host, such as the files being opened, the modifications being made, and the system calls being executed. This level of monitoring helps to identify some covert indicators of compromise that other network level monitoring would miss, for example, a user trying to access files outside their typical parameters or a user running an application that is acting atypically.

This level of deep host-specific visibility helps identify insider threats, sophisticated hidden malware like rootkits, as well as understanding an attack’s intricate kill chain after an endpoint is compromised. By documenting and analyzing relevant events on a system, HIDS furnishes security analysts with a detailed forensic trail, which allows them to reconstruct incidents, identify system weaknesses, and respond to breaches with precision, strengthening overall security posture.  

Detecting Unauthorized File Changes  

One of the core components of HIDS is the ability to identify unauthorized changes to files, particularly important system files and files that maintain the integrity of the data. HIDS usually keeps a baseline of critical system files such as executables and configuration files, and even data files. It checks these files against the baseline and uses cryptographic hashes or checksums to maintain a baseline. Any deviation triggers an alert suggesting a possible malware infection or unauthorized tampering.

This capability is critical in avoiding and mitigating many of the nefarious activities that may be undertaken. For example, it may be possible to flag in real time when a system binary is being modified by a hacker to maintain a foothold, when ransomware is in the process of encrypting files for a user, or even when a user, intentionally or otherwise, makes a change to a crucial setting. Through real-time notifications of breaches of file integrity, HIDS aids organizations in safeguarding the most vital components of their systems and data, ensuring that crucial operations are shielded and that sensitive data is not compromised.  

Monitoring and Recording Security Events  

As far as event monitoring and recording for security purposes are concerned, HIDS is particularly good at the monitoring and recording of a number of security events at the host it safeguards. Such events include application crashes, user login and logoff events, breaches of defined security thresholds, alterations of user security roles, as well as process creation and termination. Through the collection of rich event streams, it is possible for HIDS to generate comprehensive audit logs that are useful for monitoring security in real-time and for incident response.

These extensive logs fulfill many functions. They offer data to anomaly detection engines that look for suspicious activities that could signify an attack. They assist in providing critical evidence in understanding attacks for post-incident investigation. They uncover how a breach was executed, which systems were impacted, what data was accessed, and how the vulnerability could be remediated. Strong logging policies implemented by HIDS frequently assist in fulfilling compliance mandates by offering auditable documentation for system logs, security events, and activities, enforcing compliance and meticulous care in the safeguarding of critical data.  

Primary Risks Identified by HIDS  

With the help of HIDS, a myriad of security risks can be identified, including but not limited to the following:  

• Overflow Buffer: The exploitation of software by the overflow of excessive data to be processed and the possibility to rewrite memory and execute arbitrary code.  
• Malicious Attacks: Trojans, rootkits, keyloggers, and spyware are attempts to hide in the host system.  
• Privilege Escalation: The unauthorized elevation of access to systems by users.  
• Configuration Changes: Monitors critical documents, registries, or settings for unauthorized alterations.  
• Mysterious Logins: Monitors odd hour or multiple unsuccessful access attempts that may be unauthorized or brute-force attempts.

How Does HIDS Work?  

HIDS tools monitor the internal environment of a host for irregularities. Here’s a detailed explanation of a typical workflow: 

What is HIDS

• Data Collection: This step involves the retrieval of information from system and application logs, the file system, system calls, and user actions.  
• Baseline Establishment: Forms a baseline for ‘normal’ activity to use for comparison.  
• Detection Mechanisms:  
• Signature-based Detection: Looks for activity within the monitored system that matches the data stored in the threat database.  
• Anomaly-based Detection: Looks for irregularities that fall outside the set parameters.  
• Alerting: Thresholds are set for both suspicious and known malicious activity. When these thresholds are crossed, alerts are triggered.  
• Reporting and Response: All the actions are logged and automated or manual action can be initiated based on the previously defined policies.  

Types of HIDS  

Systems of Host Based Intrusion Detection differ on the basis of their functions and methods of threat detection.  

File Integrity Monitoring (FIM):  

• Monitors the set of changes on the files and the directories.  
• Important in detecting changes in the configuration or system files that are not authorized.  

Log File Monitoring:  

• Review system and application logs for unusual activity and irregular sequences of events.  
• Useful in detecting brute force and suspicious logon attempts.  

Kernel based HIDS:  

• Monitors system calls and other low-level activities at the kernel level.  
• Gains deeper insight into the system processes.  

Application based HIDS:  

• Monitors abnormal activities in certain applications.  
• Applicable to web servers, databases, and critical business application components.

HIDS Tools: Top Software Solutions   

There are a multitude of HIDS tools readily available, both proprietary and open-source. The list below highlights some of the HIDS tools:  

OSSEC (Open Source Security):  

• Open-source HIDS solution.  
• Offers log analysis, file integrity checking, rootkit detection, and real-time alerting.  

Wazuh:  

• OSSEC augments OSSEC with additional features.  
• Uses ELK stack for visualization.  
• Includes threat intelligence feeds.  

AIDE (Advanced Intrusion Detection Environment):  

• Emphasis of this module is on file integrity checking.  
• Lightweight and customizable.  

Tripwire:  

• Provides one of the earliest commercial HIDS solutions.  
• Strong offer of file integrity monitoring and policy compliance.  

Samhain:  

• Good for big environments.  
• Has centralized logging and tamper detection capabilities.  

Security Onion:  

• Primarily a NIDS solution, but includes HIDS functionality through auxiliary tools.  

Obstacles in Setting Up HIDS  

Despite the advantages of HIDS, its limitations and challenges are noteworthy:  

• Performance Cost: The HIDS system placed on the hosts will have a more significant impact on system resources.  
• Managing hundreds or thousands of endpoints with HIDS will require considerably more effort, which complicates the issue of scalability.  
• Frequency of alerts may go up as a result of detection systems (signature and anomaly-based) generating an excessive number of false alerts.  
• Regular updates and modifications are necessary in order for the system to be useful.  
• HIDS can monitor for system data that has been decrypted, but relevant information and threats that are hidden within encrypted data are likely to be overlooked. Unlike NIDS, they cannot monitor the encrypted data.

Best Practices for Effective HIDS Implementation 

For optimal utilization of HIDS software, observe the following best practices:

• Use Together with NIDS: Using HIDS along with NIDS provides greater insights and offers defence in depth.
• Alter Signatures and Rules: Change the preconfigured signatures to defaults that apply in your case.
• Manage from a Single Point: A Zulu offers centralized configuration and management for HIDS systems simplifying administration.
• Reactive Actions: Response time improvements can be made through time by automating actions for certain triggers.
• Use Together with a SIEM: Integrate HIDS with a Security Information and Event Management (SIEM) for holistic assessment.
• Use Regularly: Do not use HIDS tools without regularly updating the signatures.
• Schedule Periodic Audits: Regularly review patterns and anomalies of logs.

Use Cases of HIDS

Healthcare

The healthcare industry relies on HIDS to protect sensitive patient information and guarantee the uninterrupted functionality of critical hospital systems. To safeguard critical hospital systems, hospitals can install HIDS on systems to protect sensitive patient databases and store electronic health records. HIDS enables hospitals to monitor patient databases for any unauthorized access and monitor sensitive configurations to ensure no unauthorized modifications are made. HIDS capability is essential for the protection of sensitive patient information in relation with compliance to legal frameworks like HIPAA along with operational continuity needed to avert critical services disruption that risk healthcare and unauthorized exposure of confidential information.

Financial Services

HIDS acts as a crucial safeguard for financial institutions by protecting their assets and client accounts from both internal and external dangers. HIDS is set up on a financial organization’s servers that process transactions, manage customer accounts, and run trading platforms. It can detect anomalies like an account’s unauthorized alteration, security control circumventions, and employee policy contraventions. Its effectiveness in tracking system calls, file alterations, and login records gives in-depth information about potential fraud or compliance violations and helps banks and financial institutions counter risks that can cause heavy financial damage and loss of client trust.

Government Agencies

Government agencies, including those focusing on national security, sensitive infrastructure, and classified data, heavily depend upon HIDS for the preservation of their system and data integrity and confidentiality. By employing HIDS on servers storing classified documents, intelligence databases, and operational control systems, agencies are able to sense very subtle signs of espionage, cyber warfare, or even insider threats. HIDS enables detection of unauthorized installations of critical applications, suspicious access to sensitive data, or unauthorized changes to system configurations, which can endanger the security of a nation or critical government operations.

E-commerce Platforms  

Due to the high amount of sensitive information such as payment methods and other personal details managed by e-commerce platforms, they become a target for cyberattacks. HIDS is very useful to the e-commerce sector because it offers protection for web servers and database servers as well as the backend infrastructure by securing them with web, database, and application firewalls. It also protects the e-commerce platform from losing sensitive customer financial data and integrity by disabling payment gateway tampering, code injection, and customer database trespassing. This ensures data protection compliance, prevents data breaches, and builds customer trust.  

Conclusion: Is HIDS Enough?  

In the system of multi-layered security, a Host-Based Intrusion Detection System plays an important part. It is the weakest system compared to other systems integrated, and serves to fortify the system with the last line of protection. At the other end, HIDS is the first line of attack, and can defend against Buffer Overflow Attacks, Denial of Service Attacks, and other malicious interventions.  

The security of the system is best off when integrated with other systems like firewalls, anti-malware programs, and NIDS. Having a distinct set of strengths and weaknesses can truly empower an organization to implement best practices by fortifying the system against an elaborate web of cyber threats.