07 Oct, 2024

#endpoint security #threat hunting #TH200 #OffSec

Hunting on Endpoints: Insights from OffSec TH-200 Course module 5 Section 1

In an era of increasing cyber threats, endpoint threat hunting enables proactive identification of malicious activities on devices, focusing on Indicators of Compromise (IoCs) such as network-related, file-related, and behavioral IoCs. Logs, especially enhanced by Sysmon, are vital for uncovering suspicious behavior. Modern security relies on Endpoint Detection and Response (EDR) solutions that offer deep insights and active threat response capabilities, surpassing traditional antivirus tools.

Preston Zen

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Hunting on Endpoints: Insights from OffSec TH-200 Course module 5 Section 1

In today’s world, our workstations, servers, and mobile devices are more vulnerable than ever. They are prime targets for cybercriminals looking to execute malicious code and infiltrate networks. With the rise of sophisticated attacks, it’s critical to get ahead of the game—and that's where endpoint threat hunting comes in.

Rather than waiting for threats to strike, endpoint threat hunting allows security teams to proactively seek out suspicious activities on devices before they become a serious problem. It’s about staying one step ahead and ensuring your organization’s data and systems remain secure.

Cracking the Code: Indicators of Compromise (IoCs) to Watch

When hunting on endpoints, threat hunters focus on three primary types of Indicators of Compromise (IoCs):

Network-related IoCs: Suspicious IP addresses, domains, or URLs tied to known malicious activities.
File-related IoCs: Unique identifiers like file hashes (MD5, SHA-256) and suspicious file behavior that hint at potential threats.
Behavioral IoCs: User activities or system behaviors that deviate from the norm, signaling something is off.

These IoCs are the bread and butter of identifying malicious activities. But not all IoCs are created equal—each type provides different clues about what’s happening on your endpoints.

Think of these as red flags within your network traffic—IP addresses or domains that point directly to bad actors. These have been covered in detail in previous modules, so let’s dive into something more dynamic.

File hashes are like fingerprints—every file has a unique one. By comparing file hashes to known malware, you can quickly flag files that pose a threat. But be warned: sophisticated attackers frequently change file signatures, so it’s crucial to stay vigilant and up to date.

Behavioral IoCs

This is where things get interesting. Unlike static indicators like file hashes, behavioral IoCs look at the bigger picture—patterns in how users or systems behave. If a process is running that shouldn’t be, or if users are suddenly doing things they’ve never done before, it could point to malicious activity.

The Power of Logs: Your Key to Hunting Success

Logs are a treasure trove of information. Whether it’s user login data or system errors, logs tell the story of what’s happening across your endpoint devices. However, not all logs are created equal, and sometimes default configurations don’t give you the detailed info you need.

Enter Sysmon: Your Logging Sidekick

For enhanced logging, Sysmon is a game-changer. Part of Microsoft’s Sysinternals suite, Sysmon provides detailed logs like process creation events, image load events, and more. These logs are invaluable in detecting suspicious activities like DLL injections or process hijacking.

EDR Solutions: The Modern Hunter’s Toolkit

Gone are the days when antivirus software was enough. Today, Endpoint Detection and Response (EDR) solutions are the gold standard in defending against endpoint threats. These tools don’t just look for known malware—they also monitor processes, network activity, and behavioral patterns in real-time.

Feature	Antivirus (Legacy)	EDR (Modern)
Threat Detection	Recognizes known malware signatures.	Detects advanced, behavior-based threats.
Visibility	Limited visibility into device activity.	Deep insights into processes, files, and network traffic.
Response Capabilities	Basic isolation/removal of known threats.	Active responses to suspicious behaviors (e.g., kill processes).

Popular EDR tools include CrowdStrike Falcon, SentinelOne, Microsoft Defender, and Elastic EDR. These tools help security teams monitor endpoint activity, analyze potential threats, and respond to incidents in real-time. By integrating with SIEM solutions, EDR enhances threat visibility across the organization.

Key Strategies for Endpoint Threat Hunting

Successful threat hunting is not about relying on one single approach. Combining intelligence-based hunting (using known IoCs) with hypothesis-based hunting (exploring potential attack scenarios) will give you the upper hand.

Threat Hunting Concepts and Practices - Insights from OffSec TH-200 Course module 1

The Offsec TH-200 course's Module 1 covers threat hunting in cybersecurity, focusing on proactive detection of threats as opposed to reactive SOC alerts. Threat hunting is categorized into in-house teams and third-party services, which enhance security by offering various detection solutions. The Threat Hunting Maturity Model outlines five levels of implementation based on data collection and analysis sophistication. Effective threat hunting consists of triggering a hypothesis, investigating, and resolving threats.

Communication and Reporting for Threat Hunters: Insights from OffSec TH-200 Course module 3

In OffSec TH-200 Module 3, the importance of timely intelligence and effective communication in threat hunting is highlighted. Key concepts include leveraging Operational, Tactical, and Technical Threat Intelligence for detecting threats like Emotet, and employing the Traffic Light Protocol (TLP) for secure and controlled information sharing during incidents to prevent data breaches.

Threat Hunting With Network: Insights from OffSec TH-200 Course module 4

This write-up details the investigation of a ransomware incident involving CLIENT02, focusing on network artifacts such as IDS logs and Splunk queries to identify IoCs related to LockBit ransomware. The process involves using threat intelligence tools to analyze destination IPs and full packet captures with Wireshark, aiming to track down the origin of the attack.

Understanding Threat Actors: Insights from OffSec TH-200 Course module 2 section 1

In OffSec TH-200 Module 2, Section 1, key cybersecurity threat actors are explored, including cybercriminals like script kiddies, hacktivists, and ransomware groups, as well as sophisticated APTs and insider threats. Each group possesses distinct motivations and impacts on organizations, necessitating robust defense strategies.

Ransomware Actors and Their Strategies: Insights from OffSec TH-200 Course module 2 section 2

Ransomware actors, motivated by financial gain, utilize tactics like phishing, exploiting vulnerabilities, and Initial Access Brokers to infect systems. The Ransomware-as-a-Service model enables lesser-skilled criminals to profit from these attacks. The attack process includes encryption, ransom demand, and payment typically in cryptocurrency. Modern strategies include double and triple extortion, combining data encryption with data theft to pressure victims.

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