Threat hunting has become an indispensable capability for security teams looking to get ahead of attackers that have evaded traditional defenses. This comprehensive guide will explore what threat hunting entails, provide actionable steps for executing threat hunts, outline real-world use cases, and equip you with the knowledge needed to uncover threats in your environment.
What is Threat Hunting and Why Does it Matter?
Threat hunting is the proactive pursuit of unknown threats and abnormalities that exist within an environment. It‘s driven by human intuition and expertise,Going beyond traditional monitoring for known bad activity, threat hunting aims to discover hidden attacker behaviors, tactics, and weaknesses defenders can fix before they are exploited.
While no security solution provides impenetrable defense, dedicated threat hunting provides a vital safety net to catch elusive attackers. Studies show average dwell time – the duration threats exist undetected – can now be over 100 days. Skilled hunters find these needles in the haystack.
"Threat hunting assumes compromise and creatively thinks about how attacks unfold from the adversary’s point of view." – David Bianco, Scythe.
Forbes notes that 55% of organizations now run threat hunting programs. And this number will only grow as skills and tools become more accessible.
Let‘s explore why threat hunting matters:
Earlier threat discovery: Hunting shortens dwell time to minimize damage from intrusions.
Uncover unknown threats: Hunt to find stealthy attacks that evade alerts and monitoring.
Bolster defenses: Lessons from hunting strengthen detection and prevention capabilities.
Enrich security skills: Hunting develops analyst mindset to better understand the attacker view.
Now let‘s dive deeper into how threat hunting works and steps your organization can take to leverage this important capability.
Inside the Threat Hunting Process
Modern threat hunting follows a clever iterative approach centered around hypotheses, leads, investigation, and response. By adopting a methodology hunting can systematically uncover hidden threats versus ad hoc guesswork.
Here are the key phases:
Hypothesize – Based on knowledge of tools, tactics, and past incidents, analysts creatively hypothesize how an attack might unfold. This grounds the hunt in likely threat scenarios versus shooting in the dark.
Search – Hypotheses drive the search for data points that could indicate malicious activity.Whether log analysis, endpoint scans, or network traffic, hunters piece together breadcrumbs.
Investigate – Strange anomalies or patterns trigger deeper investigation to confirm and understand potentially malicious behavior.
Respond – Confirmed threats lead to containing the incident and remediating to bolster defenses against similar attacks.
By leveraging intuition, analytics, and creativity through these structured steps, hunts reveal oversights in defenses for decisive response.
"Threat hunting is much like piecing together a puzzle — you need to organize the pieces into a picture to derive meaning from them” explains threat hunter Sarah Hawley in an Infosecurity Magazine interview.
Now let’s explore 5 keys for unlocking successful threat hunts.
5 Keys to Unlocking Successful Threat Hunts
1. Ask Clever “What If” Questions
Savvy hunters brainstorm creative questions focused on probable attack tactics:
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What if ransomware got in via this vulnerable app?
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What if an insider is stealing data using FTP?
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What if attackers backdoored our DNS server?
These hypothetical questions anchor hunts in risky scenarios that could be unfolding.
2. Understand Attacker Tools & Tactics
Hunting is most effective when grounded in how adversaries operate based on factors like:
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Common initial access vectors like phishing
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Malware families seen targeting your industry
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Cybercrime group TTPs from threat intel feeds
This informs high-value hunting hypotheses aligned to real-world attacks.
3. Analyze Event Data & Activity Trails
Look for unusual access points, unknown users, privilege misuse, or payload delivery across:
- Authentication systems
- DNS traffic
- Command line access
- PowerShell execution
- External communications
Piecing these breadcrumbs together tells stories of potential breaches.
4. Inspect Endpoints & Infrastructure
Threat hunting extends across devices, servers, cloud instances, containers, IoT devices. Examine areas like:
- Active processes, services, modules
- Registry, file system changes
- Network connections
- Scheduled tasks
- Unauthorized apps/tools
Malware hide in plain sight via these means.
5. Document Themes & Narratives
As anomaly patterns emerge document potential attack narratives. This helps:
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Guide investigation with working theories
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Spot repetitions pointing to broader campaign
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Determine fixes to bolster defenses
With thoughtful hypotheses driving inquiries, hunts reveal oversights for resolute response.
Now let’s look at real-world examples of uncovering threats via hunting.
Threat Hunting Use Cases Across Industries
Threat hunting may conjure images of elite military cyber units or high-end cybersecurity firms. But hunting functions at all levels. Even modest programs with limited tools hunt effectively.
Hunting success stems more from analyst creativity and business know-how than budgets. Let‘s examine threat hunt stories across different industries.
Healthcare Threat Hunting
Healthcare relentlessly fights data-motivated attackers. As ConnectWise reports:
- 94% of healthcare organizations suffered data breaches
- Breaches cost $7.3 million per incident on average
What could hunting uncover in such environments? Carbon Black offers a healthcare hunting example revealing stealthy ransomware.
Analysts noticed anonymous logins to a nursing desktop via Microsoft RDP. This warranted further endpoint inspection revealing:
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Suspicious child process injection into svchost
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Encryption functionality activating
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File extensions changing enterprise-wide
This urgent ransomware incident may have unfolded for months if not discovered mid-hunt.
Financial Services Threat Hunting
Holding the crown for most breached industry, banking and insurance present lucrative targets. As Deloitte’s 2022 threat report observes:
- Financial services saw 41% of breaches in 2021
- Average cost of breach is $5.72 million
So what may hunts find lurking within financial systems? Enterprise Times details a hunting story illuminating compromised credentials.
Analysts noticed anomalies in HR data access patterns. Hunting hypotheses prompted further inspection revealing unauthorized database queries. An insider had stolen credentials to steal employee tax records.
This breach evaded firewalls and antivirus. Only active threat hunting practices revealed the attack.
Retail Threat Hunting
Handling payments and consumer data, retailers face increasing exposure to cyber attacks. As Applied Risk details, key retail threats include:
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POS malware scraping payment card data
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Supply chain attacks hijacking updates
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Ransomware crippling operations
Could hunting identify retail threats before major damages occur? Dark Reading recently profiled hunting efforts by supermarket chain Giant Eagle.
Analysts leverage AI to analyze patterns across 9 billion monthly security events. Hunting questions focused on likely attack paths. Recently Giant Eagle’s hunt uncovered a stealthy attacker performing reconnaissance while preparing to deploy ransomware.
Overcoming Key Threat Hunting Challenges
While highly effective, threat hunting introduces challenges needing mitigation like:
Data overload: High volumes of security data overwhelm limited analyst bandwidth to uncover subtle threats. Automating repetitive tasks preserves time for hunting. AI further helps surface high-fidelity alerts.
Increasing complexity: Hybrid environments with cloud, ransomware, and supply chain threats lead to exponential risk areas. Specialized platforms provide unified visibility and simplify hunting.
Talent Shortages: Expert-dependant hunting strains understaffed teams. Augmenting talent with hunting methodology, training, and automation maximizes productivity.
Limited tools/budget: Many organizations scramble with insufficient tooling. Pragmatic options exist for various budgets by prioritizing high-probability threats.
Creating a Threat Hunting Program: Key Takeaways
With threats outpacing defenses, organizations must become the hunter versus the hunted. Use these recommendations for launching an effective threat hunting program:
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Start small: Tackle hypotheses around priority assets and risks to demonstrate quick wins.
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Focus hunts: Guide efforts around detectable phases of common attack campaigns impacting your industry.
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Augment analysts: Combine human intuition with hunting platforms providing automation, AI, and playbooks.
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Drive tool decisions: Ensure tooling provides necessary data, detection, and response capabilities to enable hunting hypotheses.
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Evangelize: Share hunting success stories with leadership and business units to build support.
Effectively institutionalizing threat hunting takes time but yields invaluable risk reduction in stopping stealthy attacks.
Now over to you – what suspicious activity may already lurk within your infrastructure and data? Let the hunt begin…
