Windows Event Log Forensics - SOC Analyst Cheatsheet

Practical Guide for Event Log Analysis & Threat Hunting


Quick Reference: Critical Event IDs by Investigation Type

Investigation Type
Critical Event IDs
Log Source
What They Reveal

Account Compromise

4624, 4625, 4648, 4672

Security

Logon success/fail, privilege escalation

Lateral Movement

4624 (Type 3), 4648, 5140, 7045

Security, System

Remote logons, service creation

RDP Activity

4624 (Type 10), 1149, 21/24/25

Security, RDP logs

Remote desktop sessions

Persistence

7045, 4697, 4698, 106/140/200

System, Security, Task Scheduler

Service/task creation

Privilege Escalation

4672, 4728, 4732, 4756

Security

Admin rights, group changes

Credential Dumping

4688, 4656, 5140

Security

Process creation, object access

PowerShell Abuse

4104, 4103, 400/403

PowerShell logs

Script execution

Evidence Destruction

1102, 104

Security, System

Log clearing


Investigation Priority Matrix

Priority
Event ID
Log
Description
Investigation Use

CRITICAL

4624

Security

Successful logon

Account compromise, lateral movement

CRITICAL

4625

Security

Failed logon

Brute force, reconnaissance

CRITICAL

4672

Security

Admin privileges assigned

Privilege escalation

CRITICAL

7045

System

Service installed

Persistence mechanism

CRITICAL

4688

Security

Process creation

Execution timeline

HIGH

4648

Security

Explicit credentials

Pass-the-hash, runas

HIGH

4697

Security

Service installed (Security log)

Persistence validation

HIGH

4698

Security

Scheduled task created

Persistence mechanism

HIGH

1102

Security

Event log cleared

Anti-forensics


Core Investigation Questions

Primary Questions:

  1. Who logged in? (4624 - Account identification)

  2. From where? (Logon Type + Source IP)

  3. What did they do? (4688 - Process execution)

  4. How did they move laterally? (4624 Type 3, 7045, 5140)

  5. What persistence was created? (7045, 4697, 4698)


SOC Investigation Workflows

Workflow 1: Account Compromise Investigation (CRITICAL)

Scenario: Suspected compromised user account

Investigation Priority Order:

Step 1: Identify Successful Logons (4624)

Event ID 4624 - Successful Logon

Critical Fields:

  • SubjectUserName - Who initiated the logon

  • TargetUserName - Account that logged in

  • LogonType - How they logged in

  • IpAddress / WorkstationName - Source location

  • LogonProcessName - Process used for logon

  • TimeCreated - When

Logon Types (MEMORIZE):

PowerShell - Find Logons:

Red Flags in 4624:

  • Type 10 (RDP) from unusual IP addresses

  • Type 3 (Network) indicating lateral movement

  • Type 8 (NetworkCleartext) - plaintext password logon

  • Logons outside business hours

  • Logons from unusual workstations

  • Service accounts with Type 10 (RDP)


Step 2: Check for Failed Logon Attempts (4625)

Event ID 4625 - Failed Logon

Critical Fields:

  • TargetUserName - Account targeted

  • FailureReason - Why it failed

  • IpAddress / WorkstationName - Attack source

  • LogonType - Attack method

Common Failure Reasons:

PowerShell - Detect Brute Force:

Red Flags in 4625:

  • Multiple failures followed by success (brute force)

  • High volume from single IP (>10 failures)

  • Failed admin accounts (Administrator, admin, etc.)

  • 0xC000006D repeated (password guessing)

  • Multiple usernames from same IP (spray attack)


Step 3: Check for Privilege Escalation (4672)

Event ID 4672 - Special Privileges Assigned

Indicates: Account logged on with administrator-level privileges

Critical Fields:

  • SubjectUserName - Account that gained privileges

  • PrivilegeList - Specific privileges granted

Important Privileges:

PowerShell - Find Privilege Escalation:

Red Flags in 4672:

  • Non-admin users with 4672 events

  • SeDebugPrivilege (credential dumping indicator)

  • Service accounts with admin privileges

  • Shortly after 4624 (privilege escalation after logon)


Step 4: Identify Explicit Credentials (4648)

Event ID 4648 - Logon with Explicit Credentials

Indicates:

  • runas command used

  • Pass-the-hash attack

  • Credential theft/reuse

Critical Fields:

  • SubjectUserName - Who initiated the action

  • TargetUserName - Credentials used

  • TargetServerName - Target system

  • ProcessName - Process used (often runas.exe)

Red Flags in 4648:

  • Different user credentials than current session

  • Admin credentials used by standard user

  • Multiple 4648 events in short time (credential testing)

  • Non-runas.exe process (potentially malicious)


EvtxECmd Usage (Zimmerman Tool) - CRITICAL

Location:

Collection:

Parsing with EvtxECmd:

Basic Directory Parse:

Filter Specific Event IDs (RECOMMENDED):

Exclude Noisy Events:

Parse with Maps (Normalised Output):

Key EvtxECmd Output Columns:

  • TimeCreated - Event timestamp

  • Computer - System name

  • EventId - Event ID

  • Level - Severity

  • Provider - Log source

  • Channel - Log file

  • UserId - User SID

  • MapDescription - Readable event description

  • PayloadData1-6 - Event-specific data


Workflow 2: Lateral Movement Detection (HIGH PRIORITY)

Scenario: Detect attacker moving between systems

Key Event Correlation:

Lateral Movement Pattern:

PsExec Lateral Movement:

Source System Indicators:

Destination System Indicators:

PowerShell - Detect PsExec:


WMI Lateral Movement:

Source System Indicators:

Destination System Indicators:


RDP Lateral Movement:

Source System Indicators:

Destination System Indicators:


Workflow 3: Persistence Detection

Scenario: Identify persistence mechanisms

Key Events:

Service Creation:

Event 7045 - Service Installed (System Log)

Critical Fields:

  • ServiceName - Name of service

  • ImagePath - Executable path

  • ServiceType - Service type

  • StartType - Auto-start configuration

  • AccountName - Service account

Event 4697 - Service Installed (Security Log)

  • Same as 7045 but in Security log (requires auditing enabled)

PowerShell - Find Suspicious Services:

Red Flags in 7045/4697:

  • Image path in temp directories

  • PowerShell/cmd.exe as service

  • Random service names

  • PSEXESVC (PsExec)

  • Auto-start configuration


Scheduled Task Creation:

Event 4698 - Scheduled Task Created (Security) Event 106 - Scheduled Task Created (Task Scheduler/Operational) Event 140 - Scheduled Task Updated (Task Scheduler/Operational) Event 200 - Scheduled Task Executed (Task Scheduler/Operational)

PowerShell - Find Scheduled Tasks:

Red Flags in 4698/106:

  • Executables from temp/appdata

  • PowerShell with encoded commands

  • Hidden tasks (names with spaces/special chars)

  • High-frequency execution (every minute)

  • Tasks running as SYSTEM


Workflow 4: PowerShell Activity Investigation

Scenario: Detect malicious PowerShell usage

Key Events:

Event 4104 - Script Block Logging (MOST IMPORTANT)

Shows: Actual PowerShell commands executed

PowerShell - Analyse Script Blocks:

Event 4103 - Module Logging

  • Logs PowerShell module loading and pipeline execution

Event 400 - PowerShell Engine Start

  • PowerShell session started

Event 403 - PowerShell Engine End

  • PowerShell session ended

Event 800 - Pipeline Execution

  • Command pipeline details

Red Flags in PowerShell Events:

  • Invoke-Expression (IEX)

  • DownloadString (download and execute)

  • -EncodedCommand (obfuscation)

  • Bypass ExecutionPolicy

  • Hidden window (-WindowStyle Hidden)

  • Known attack tools (Mimikatz, Empire, Covenant)

  • Base64 encoded commands


Workflow 5: Credential Dumping Detection

Scenario: Detect credential theft attempts

Key Indicators:

LSASS Access:

Event 4656 - Handle to Object Requested

  • Process requesting access to lsass.exe

  • ObjectName: \Device\HarddiskVolume*\Windows\System32\lsass.exe

Event 4688 - Process Creation

  • Look for:

    • procdump.exe

    • mimikatz.exe

    • dumpert.exe

    • comsvcs.dll (MiniDump)

PowerShell - Detect LSASS Access:

SAM/NTDS.dit Access:

Event 4663 - Attempt to Access Object

  • Access to SAM/SECURITY/SYSTEM registry hives

  • Access to NTDS.dit (Active Directory database)


Workflow 6: Evidence Destruction Detection

Scenario: Detect log clearing and anti-forensics

Critical Events:

Event 1102 - Security Log Cleared Event 104 - System Log Cleared

PowerShell - Detect Log Clearing:

Red Flags:

  • Event 1102 or 104 at all (major indicator)

  • Shortly after suspicious activity

  • Cleared by non-admin account

  • Multiple logs cleared


Complete Investigation Script


Quick Triage Commands

Live System Quick Checks


Event Log Collection Commands


Investigation Checklists

Account Compromise Investigation

  • [ ] Check 4624 for successful logons (unusual times/IPs)

  • [ ] Check 4625 for brute force attempts (>5 failures)

  • [ ] Correlate failures with successes (same user/IP)

  • [ ] Check 4672 for privilege escalation

  • [ ] Check 4648 for explicit credential usage

  • [ ] Review logon types (Type 10 RDP, Type 3 network)

  • [ ] Identify source IPs and workstations

  • [ ] Build user activity timeline

  • [ ] Cross-reference with file access artifacts

Lateral Movement Investigation

  • [ ] Check 4624 Type 3 (network logons)

  • [ ] Check 7045 for PSEXESVC service

  • [ ] Check 4648 for explicit credentials

  • [ ] Check 5140 for share access (ADMIN$, C$)

  • [ ] Check 4688 for remote execution tools

  • [ ] Review WMI activity logs (5857, 5860, 5861)

  • [ ] Check PowerShell remote execution

  • [ ] Correlate source and destination events

  • [ ] Map lateral movement paths

Persistence Investigation

  • [ ] Check 7045 for service creation

  • [ ] Review service image paths (temp/appdata)

  • [ ] Check 4697 (Security log service install)

  • [ ] Check 4698 for scheduled tasks

  • [ ] Review Task Scheduler operational log (106, 140, 200)

  • [ ] Check registry Run keys (correlate with registry artifacts)

  • [ ] Review WMI event subscriptions

  • [ ] Validate autostart locations


Summary: Critical Event IDs (Memorise)

Top 10 Most Important

EventID
Log
Description
Priority

4624

Security

Successful logon

CRITICAL

4625

Security

Failed logon

CRITICAL

4672

Security

Admin privileges

CRITICAL

4688

Security

Process creation

CRITICAL

7045

System

Service installed

CRITICAL

1102

Security

Log cleared

CRITICAL

4648

Security

Explicit credentials

HIGH

4697

Security

Service installed

HIGH

4698

Security

Task created

HIGH

4104

PowerShell

Script block

HIGH

Key Principle

Event logs document what happened on a Windows system. Focus on logon events (4624/4625), privilege escalation (4672), persistence (7045/4698), and evidence destruction (1102). Always correlate multiple events to build the complete attack timeline.


Remember: Event logs survive many anti-forensics techniques. Even if malware is deleted, event logs show it executed. Always check for log clearing (1102/104) as first indicator of attacker awareness!

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