Threat Hunting 101 Flashcards
Prerequisites for Threat Hunting?
- SANS “Top 20” CIS Critical Security Controls is a good place to start
- Minimum requirements:
■ inventory of systems, networks, software
■ Baseline before an incident: know what’s “normal” network
■ An incident response plan in place BEFORE an incident
■ A list of known privileged accounts
■ Know where your sensitive data is located
Threat Hunting Frameworks?
MITRE ATTACK
Lockheed Martin’s Cyber Kill Chain
Fireeye’s Attack Lifecycle
Gartner’s Cyber Attack Model
Should I move from left to right when using the ATT&CK Framework while executing my exercise?
there is no specific order
Use the ATT&CK to support your hypothesis.
iIf you don’t have a hypothesis, start your threat-hunting where high-risk and first impact areas are, then work from a top-down.
Threat hunting should be focused, how?
■ Logs that matter
■ Common patterns used by attackers
■ Get a tangible result
■ Improving technique with each iteration of the hunt
What Do You Need to Start Threat Hunting?
- automated blocking and monitoring tools such as firewalls,
- antivirus, endpoint management
- network packet capture
- SIEM
- Threat intelligence
Some Threat Hunting Tools?
- Sqrrl - APT detection platform. Combines Link Analysis and UBA
- Sysmon
- FireEye-Redline
- Volatility
- Malware-Traffic- Analysis.net
- Windows Event Forwarding
- Bricata
- Cortex XDR
What is an effective cyber threat hunting process?
non-signature-based detection
anomaly- and behavior-based analytics
external threat intelligence sources
Why an analyst would start to correlate data and determine if there is cause for further investigation?
examining various sources of data, such as authentication logs or traffic flow
What are the 5 HMM levels?
HM1: Rely on IDS, Collects info from systems, Use Threat Intel feeds, Hunt is manually
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HM2: Incorporate hunt techniques from external sources, Collect data from systems, Active approach
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HM3: Analyze different data,, , Machine learning, Publish hunting procedures, Identify patterns in alerts
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HM4: HM3 capabilities + Automate tactical-level analysis, Scripts and Programs based on intelligence, Analysts can focus on creating new hunt methods
The hunting cycle is a four-stage loop ?
Hypothesize
Investigate
Uncover
Inform and Enrich
Examples of a pattern or the attacker’s TTP?
specific registry key modifications
The steps of the Hunt-Uncover stage?
Investigate specific IOCs
Link various IOCs
TTPs discovered are shared
The steps in the Inform and Enrich stage?
- Use knowledge from Uncover stage to reduce risk and simplify future hunts
- Document hunting cycle result
- Automate hunting repeatable tasks
- Create signatures and rules for threat detection systems using new findings.
What three aspects are vulnerabilities evaluated under?
In CVSS
- Base group: characteristics of a vulnerability that are constant over time
* - Temporal Group: assesses the vulnerability as it changes over time
* - Environmental Group: characteristics of a vulnerability, taking into account the organizational environment.
How scoring works for the Base Group - CVSS?
0 - 10
0 the least severe
The base group Exploitability matrix?
- Attack Vector - Scope
- Attack Complexity - Confidentiality
- Privilege Required - Integrity
- User Interaction - Availability
The temporal group Exploitability matrix?
- Exploit Code Maturity (E)
- Remediation Level (RL)
- Report Confidence (RC)
What is the importance of CVSS?
Reports - vulnerability severity - urgency - priority of response. Note: Does not calculate the chances of being attacked, but the chances of being compromised when attacked and potential damage.
How CVSS is used in Threat Hunting?
- prioritize remediation efforts.
- identify how vulnerabilities are used
Maintenance and Guidance of CVSS?
FIRTS (Forum for Incident Respoonse and Security Teams)
What are the conditions for a Hot Thread to be recorded in the database?
- Newly disclosed vulnerability with a CVSS base score of high (7.0 or greater).
* - Intelligence indicating attacks targeted at specific customers (from Talos, open source intel-sharing forums, ISACs and law enforcement)
* - Native intelligence: Growing evidence of a campaign developing on customers’ sites, a surge in reliable and high fidelity security alerts, or due to an opaque priority request to place vigilance in monitoring specific network zones for a specified time period
Threat Awareness Resources?
- OWASP
- Spamhaus Project
- Alexa and the GoatRider tool(Website traffic analysis)
- Farsight Security’s DNSDB
Threat Intelligence Sources?
- Malware detection and analysis sites
- Web content verification sites
- Network utilities
- Scripting Decoding Utilities
- Blogs and Feeds
What three aspects of an attack should a hunter look into?
- Infection Vector
- Persistence
- Lateral Movement
Open source Threat Hunting tools for smaller organizations or doing it on your own?
Host, Network, and Log Data:
GRR, SysMon, Bro, WinBeat
Storage and Analytics:
ELK Stack: Elastic, Logstach, Kibana
Infrastructure:
Puppet, Chef, Docker
Threat Hunting Skills?
Offensive Skills
Network Analysis - Host Analysis
Malware Analysis - Memory Analysis
Most importantly
- Investigative mind
- Attacker mindset
- Patience to work long hours to complete a TH exercise
- Continuously search for new threats and
- Open to use new tools or create them.
Attack Scenario - Infection Vector
External
Delivery Method: Phishing - External Download
Exploit Method: Office Macro - PDF Vulnerability
Internal
Delivery Method: USB - Network Share
Exploit Method: Native Executable - HTA
Elements of hypotheses for the areas to look into?
i.e Infection vector, Persistence, and Lateral Movement.
- What data I need?
- How do I get it?
- How do I hunt through that data?
- What data I need?
- How do I get it?
- How do I hunt through that data?
External Vectors / Perimeter Logs
- Bro logs
- Email and Proxy logs
Internal Vectors
- Process Data
- Registry
- Windows Events
Delivery Vector - Phishing - Office Macro Exploit used
What data do I need?
- Process execution data
- Enhanced Powershell logging
- Email logs
- Process execution data
- Enhanced Powershell logging
- Email logs
Where do I get the data from?
- Sysmon/OSquery
- Windows Event logs
- Email Servers
- Sysmon/OSquery
- Windows Event logs
- Email Servers
How to hunt through this data?
- Searching Office programs launching Powershell
- Command arguments w/encoded command
Then query Kibana for that data to get a visualization for that pattern and attack
How do attacker establish Persistence?
Traditional
- Run keys - Services - Scheduled Tasks
Creative/Stealthy
- Office Templates
- Hijacking Windows features (Applnit DLLs/Accessibility features)
Host Analysis skills
Persistence example - RUN KEYS
What data is needed?
Where to get the data from?
How to hunt through the data?
What? Registry Run Key locations Run, RunOnce, RunOnceEX Where? Powershell script Group policy to deploy Collect to Elastic How? Grouping of executable in run key values Grouping of executable paths Command line commands/Arguments Hashing First seen/last run
Lateral Movement
Two key areas to look into for evidence?
Recon
DNS Zone Transfers, LDAP Enumeration, Port Scanning
Access
PSExec - RDP - PS Remoting
Recon
DNS Zone Transfers, LDAP Enumeration, Port Scanning
Access
PSExec - RDP - PS Remoting
Where do I find the data?
- WVT logs
- Bro/Network logs
- Enumeration artefacts
- IDS log parsing
Four Primary Threat Hunting Techniques?
Searching
Clustering
Grouping
Stack Counting