All About IOC Feeds [Introducing our New Feature]
Table of contents
How do you spot a cyber threat before it’s too late? For security teams, every second counts. Attackers are constantly evolving, using new techniques to breach systems, steal data, and disrupt operations.
Indicators of Compromise (IOCs) act as digital breadcrumbs that help identify vulnerabilities and malicious activity before they cause damage. IOC feeds provide a continuous stream of known threat indicators, equipping security teams with the insights to proactively detect and neutralize threats.
1. What are IOC feeds?
Indicators of Compromise (IOCs) are pieces of forensic data that signal potential malicious activity. After analysis, an IOC is an asset identified as such when there are sufficient elements indicating its involvement in a past, current or even future cyber attack.
These could be IP addresses, domain names, urls, hostnames, hashes, email addresses, payloads of malware or other digital artifacts associated with cyber threats.
An IOC feed, or threat feed, is a continuously updated list of these indicators, sourced from government agencies, threat intelligence vendors, dark web communication channels, and cybersecurity researchers.
There are several different types of IOC feeds, including:
- Free/ Public feeds: Maintained by open-source threat intelligence feeds and communities, such as the MISP project.
- Commercial feeds: Provided by cybersecurity vendors, offering curated and validated intelligence, usually as anonymized metadata.
- Proprietary feeds: Developed internally by organizations based on their threat landscape.
- Dark web feeds: Monitors dark web forums for infected websites or domains for sale.
- Government and NGO feeds: Offered as a complementary service or for a fee, such as the FBI’s InfraGard program (below).
FBI video introducing their InfraGard program.
2. The benefits of IOC feeds
An IOC feed is just like having a virtual spy network. It can proactively investigate any recent or past dangers, so that you can shut them down in real-time.
The IOC feed plays a crucial role in detecting threats across various stages of a cyber attack. Whether it’s during reconnaissance, when attackers are gathering information, or later stages like weaponization, delivery, and exploitation, IOCs help identify potential threats.
They continue to provide value as the attack unfolds, aiding in the detection of installation, command and control activities, actions on objectives, and even exfiltration efforts. By leveraging IOCs, organizations can enhance their ability to respond effectively throughout the entire attack lifecycle.
Here is why IOC feeds are essential for any organization.
- Faster threat hunting: With cyber threat intelligence feeds, CISOs and security teams can quickly intercept and mitigate cyberattacks in progress or even detect them before they happen. For instance, if a known malicious IP attempts to access your network, an IOC feed helps flag and block it instantly.
- Automated security response: Security tools like SIEMs, firewalls, and endpoint protection platforms (EPPs) can automatically integrate with IOC feeds. This automation enables real-time blocking of malicious entities, reducing manual workload for IT teams.
- Improved incident response procedures: Even if a cyber threat slips through the cracks, IOC feeds can correlate network activity and identify the root cause.
3. How IOC feeds work: The technical components
Here’s everything you need to know about how IOCs work—from the different types, to the formats and protocols they follow, to how they integrate with security tools.
Types of IOCs
Here are the main indicators of compromise to be aware of. You can visit CISA’s ‘Known Exploited Vulnerabilities Catalog’ for the full list.
- IP addresses: Malicious servers used for phishing, malware delivery, or botnet activity.
- Domain names: Fraudulent or compromised domains used for scams, C2 communication, or data exfiltration.
- File hashes: Unique identifiers for malware-infected files that might be used in a ransomware attack, such as from RansomHub, Akira, or LockBit.
- Email addresses: Used in phishing campaigns or business email compromise (BEC) scams.
- URLs: Links leading to malicious content or exploit kits.
- DNS protocols: Targeting a system with abnormally high volumes of DNS traffic, for example.
Formats and protocols
IOC feeds are often shared in structured formats such as:
- STIX (Structured Threat Information eXpression): A standardized format for sharing threat intelligence.
- TAXII (Trusted Automated eXchange of Indicator Information): A protocol for exchanging threat data between systems.
- JSON & CSV: Common formats used for compatibility with security tools.
Integration with security tools
IOC feeds integrate with various security solutions, including:
- SIEM (Security Information and Event Management): Centralized log analysis for threat detection.
- EDR (Endpoint Detection & Response): Identifying and blocking malicious activity on endpoints.
- Firewalls & IDS/ IPS: Blocking malicious traffic in real-time.
- TIP (Threat Intelligence Platform): Enrichment of a threat knowledge database
4. IOC feed best practices
Whether it’s open-source feeds, dark web monitoring feeds, or otherwise, here are some IOC best practices to follow.
Use multiple threat intelligence sources
It’s generally better to rely on multiple threat data feeds. While an exhaustive collection of Indicators of Compromise (IOCs) may seem like an ideal goal, it’s often unattainable. Instead, it’s crucial to diversify the sources of IOCs to ensure comprehensive coverage of external threats. By gathering IOCs from multiple trusted sources, organizations can enhance their ability to remediate, faster! This approach helps mitigate the limitations of relying on a single set of indicators, which might not capture the full scope of potential threats.
By combining diverse IOCs, organizations can strengthen their cybersecurity posture and improve their incident response strategies.
With cyber threat intelligence from multiple sources, it’s far easier to stay ahead of cybercriminals.
Here’s how.
- A wider variety of data: You get a more comprehensive overview of your threat landscape.
- Enhanced verification: You can cross-check potential threats to avoid false positives.
- Multi-layered security: You can rely on multiple IOC feeds to detect a threat, even if one threat intelligence feed fails.
Focus on high-confidence IOCs
Some threat intelligence platforms can be outdated or deliver broad information, which can generate false positives.
A relevant IOC feeds is characterized by four main issues: data quality and contextualization, false positive management, volumetry, and ease of integration with third-party security tools.
- Data quality: By contextualizing and enriching the data, the analyst in charge of processing alerts will easily understand the threat at hand.
- FP management: Setting up a lifecycle dedicated to each IOC typology and source, as well as actively searching for false positives (absolutely no one wants to receive an internal IP identified as an IOC in an IOC Feeds), will increase the quality of coverage and reduce overall processing time for analysts.
- Volume: An extensive range of relevant data will necessarily increase the level of coverage on external threats.
- Integration with third-party tools: Between the moment an IOC is detected and qualified, and the moment it is put under surveillance in a third-party tool, very few (if any) human intervention needs to be involved. The time between detection and monitoring should be as short as possible.
Cross-check your IOC feed data
A recent Forbes article pointed out that false positives are a big challenge with IOC feeds.
For example, legitimate services like Microsoft Windows Update, Cisco, AWS, or Zoom can sometimes be flagged—disrupting normal business processes.
To counteract this, make sure you:
- Validate the data: Cross-check your data, such as with reputation databases, to make sure it’s correct.
- Automate your processes: Have regular updates to avoid stale data, and implement automatic false positive remediation procedures.
- Enforce time limits: Remove IOCs after a set period to avoid ‘benign IPs being flagged as malicious over time.’
Sync IOC feeds with your wider strategy
Threat landscapes can change quickly. Ensure that your IOC feeds are updated frequently and that your security policies adapt to new attack techniques.
For example, some indicators of compromise might become obsolete or irrelevant, while new warning signs could appear.
In general, your IOC feeds should complement, not replace, broader threat intelligence efforts. Combine IOC-based detection with other tools, such as API security testing, and other forms of external attack surface management (EASM).
A post about EASM on CybelAngel’s X channel.
5. IOC use cases
What do IOC feeds look like in action? Here are some quick examples.
- Blocking malicious IPs: When an IP address associated with a known phishing campaign attempts access, the system automatically blocklists it, preventing potential fraud. If an internal computer is secretly communicating with an external server that is known to be used for controlling compromised systems (C2), it could indicate that a cyber attack is happening without being detected
- Detecting malware: When an employee unknowingly downloads an infected file, the EDR solution cross-references the hash against the feed, quarantining the file before it spreads.
- Threat hunting: SOC analysts proactively search logs for IOCs linked to Advanced Persistent Threat (APT) groups. By identifying unusual activity early, they prevent attackers from gaining a foothold in the network, and add them to a blacklist.
- Supply chain security: A company monitors third-party vendors for compromised assets. When an IOC feed reveals a vendor’s system is linked to a recent data breach, security teams take immediate action to prevent exposure.
6. Real-time Threat Detection and Blocking with CybelAngel’s IOC Feed”
If you’re looking for an IOC feed to complement your cybersecurity posture, then CybelAngel could be the right fit.
CybelAngel is an external threat intelligence solution designed to safeguard all your public-facing digital assets—from preventing data breaches, to monitoring the dark web.
It also offers a comprehensive threat intelligence service, which includes:
- Fast, data-driven insights: Identify (and block) any compromises in record time.
- Rich curated context: Digest handpicked deep insights from threat data and risk scores.
- Adversary tactics: Spot what hackers are doing, and stop them in their tracks.
- Behavioral analytics: Catch unusual activity before it does any harm.
- Attack trends: Compare your data with recent cybercriminal activities.
- Simple integrations: Connect with your security tools and let it run on autopilot.
- No false positives: Cross-reference your data from multiple sources.
Whether you need instant alerts or deeper investigation support, CybelAngel delivers the intelligence you need to enhance your security operations.
To see the tool in action, simply book a call, and the team would be delighted to show you around.
7. FAQs on IOC feeds
IOC feeds are a crucial tool for detecting and mitigating cyber threats before they escalate. Here are some commonly-asked questions that everyone should know.
What are IOC feeds?
IOC feeds are data streams of known indicators of compromise (IP addresses, domains, file hashes, email addresses etc.) that help security teams detect and block cyber threats.
What does an IOC do?
An indicator of compromise (IOC) acts as a warning signal for potential malicious activity, allowing security teams to investigate and respond to threats quickly.
What is an IOC indication?
An IOC indication refers to a specific event or data point that suggests a security compromise, such as an IP address linked to malware activity.
What is an IOC and SOC?
An IOC (Indicator of Compromise) is a piece of threat data, while a SOC (Security Operations Center) is a team responsible for monitoring and responding to security incidents. SOCs rely on IOCs to detect and mitigate cyber threats.
What is threat intelligence?
Threat Intelligence refers is the process of collecting, analyzing, and disseminating information about potential or existing cyber threats. The goal of CTI is to provide actionable insights that help organizations anticipate, prevent, and respond to cyber threats more effectively.
Wrapping up
Having an IOC security feed is an essential part of any CISO checklist. With the right data and insights, you’ll be equipped to tackle cybercriminals head-on, and keep your organization safe.
CybelAngel’s on-demand threat intelligence service provides curated, high-value IOCs that empower your security team to act with confidence.
Why not request a demo to see its threat intelligence workflows in action? (No commitment required—just enjoy a detailed walkthrough of how you could simplify your security operations.)