mukul975/analyzing-powershell-script-block-logging
skills/analyzing-powershell-script-block-logging/SKILL.md
Parse Windows PowerShell Script Block Logs (Event ID 4104) from EVTX files to detect obfuscated commands, encoded payloads, and living-off-the-land techniques. Uses python-evtx to extract and reconstruct multi-block scripts, applies entropy analysis and pattern matching for Base64-encoded commands, Invoke-Expression abuse, download cradles, and AMSI bypass attempts.
$ install --global
skillsauthnpx skillsauth add mukul975/anthropic-cybersecurity-skills analyzing-powershell-script-block-loggingInstall this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
Security Scan Results
3 of 9 scanners reported clean
Some scanners were skipped, did not run, or reported a non-clean status. Review each row below.
3
Scanners Passed
9
Scanners in report
Clean
TrivyContainer and dependency vulnerability scanner
95%
Clean
SemgrepStatic code analysis for vulnerabilities
95%
Clean
mcp-scan (Snyk)Model Context Protocol security validation
95%
Skipped
Snyk (dep)Open source security scanning
50%
Skipped
Socket.devSupply chain security analysis
50%
Skipped
VirusTotalMulti-engine malware detection
50%
Skipped
CrowdStrikeAdvanced threat intelligence
50%
Skipped
OSV-ScannerOpen Source Vulnerability database check
50%
Skipped
OWASP Dep-Check
50%
Last scanned: Jun 2, 2026, 3:53 AM230.9s3 files scanned
SKILL.md
- name:
- analyzing-powershell-script-block-logging
- description:
- Parse Windows PowerShell Script Block Logs (Event ID 4104) from EVTX
- domain:
- cybersecurity
- subdomain:
- security-operations
- version:
- 1.0
- author:
- mahipal
- license:
- Apache-2.0
Analyzing PowerShell Script Block Logging
When to Use
- When investigating security incidents that require analyzing powershell script block logging
- When building detection rules or threat hunting queries for this domain
- When SOC analysts need structured procedures for this analysis type
- When validating security monitoring coverage for related attack techniques
Prerequisites
- Familiarity with security operations concepts and tools
- Access to a test or lab environment for safe execution
- Python 3.8+ with required dependencies installed
- Appropriate authorization for any testing activities
Instructions
- Install dependencies:
pip install python-evtx lxml - Collect PowerShell Operational logs:
Microsoft-Windows-PowerShell%4Operational.evtx - Parse Event ID 4104 entries using python-evtx to extract ScriptBlockText, ScriptBlockId, and MessageNumber/MessageTotal for multi-part script reconstruction.
- Apply detection heuristics:
- Base64-encoded commands (
-EncodedCommand,FromBase64String) - Download cradles (
DownloadString,DownloadFile,Invoke-WebRequest,Net.WebClient) - AMSI bypass patterns (
AmsiUtils,amsiInitFailed) - Obfuscation indicators (high entropy, tick-mark insertion, string concatenation)
- Base64-encoded commands (
- Generate a report with reconstructed scripts, risk scores, and MITRE ATT&CK mappings.
python scripts/agent.py --evtx-file /path/to/PowerShell-Operational.evtx --output ps_analysis.json
Examples
Detect Encoded Command Execution
import base64
if "-encodedcommand" in script_text.lower():
encoded = script_text.split()[-1]
decoded = base64.b64decode(encoded).decode("utf-16-le")
Reconstruct Multi-Block Script
Scripts split across multiple 4104 events share a ScriptBlockId. Concatenate blocks ordered by MessageNumber to recover the full script.
Related Skills
mukul975/detecting-lateral-movement-with-splunk
data-ai
VerifiedTrustedCommunity
Detect adversary lateral movement across networks using Splunk SPL queries against Windows authentication logs, SMB traffic, and remote service abuse.
21,866SKILL.mdUpdated Jun 27, 2026
mukul975/detecting-lateral-movement-in-network
testing
VerifiedTrustedCommunity
Identifies lateral movement techniques in enterprise networks by analyzing authentication logs, network flows, SMB traffic, and RDP sessions using Zeek, Velociraptor, and SIEM correlation rules to detect attackers moving between systems.
21,866SKILL.mdUpdated Jun 27, 2026
mukul975/detecting-kerberoasting-attacks
tools
VerifiedTrustedCommunity
Detect Kerberoasting attacks by monitoring for anomalous Kerberos TGS requests targeting service accounts with SPNs for offline password cracking.
21,866SKILL.mdUpdated Jun 27, 2026
mukul975/detecting-insider-threat-with-ueba
development
VerifiedTrustedCommunity
Implement User and Entity Behavior Analytics using Elasticsearch/OpenSearch to build behavioral baselines, calculate anomaly scores, perform peer group analysis, and detect insider threat indicators such as data exfiltration, privilege abuse, and unauthorized access patterns.
21,866SKILL.mdUpdated Jun 27, 2026