System Administration

DeepBlueCLI – PowerShell Module for Threat Hunting via Windows Event Logs

DeepBlueCLI - a PowerShell Module for Threat Hunting via Windows Event Logs

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DeepBlueCLI – a PowerShell Module for Threat Hunting via Windows Event Logs

Eric Conrad, Backshore Communications, LLC

deepblue at backshore dot net

Twitter: @eric_conrad

http://ericconrad.com

Sample evtx files are in the .evtx directory

Usage:

.DeepBlue.ps1 <event log name> <evtx filename>

See the Set-ExecutionPolicy Readme if you receive a ‘running scripts is disabled on this system’ error.

Process local Windows security event log (PowerShell must be run as Administrator):

.DeepBlue.ps1

or:

.DeepBlue.ps1 -log security

Process local Windows system event log:

.DeepBlue.ps1 -log system

Process evtx file:

.DeepBlue.ps1 .evtxnew-user-security.evtx

Windows Event Logs processed

  • Windows Security
  • Windows System
  • Windows Application
  • Windows PowerShell
  • Sysmon

Command Line Logs processed

See Logging setup section below for how to configure these logs

  • Windows Security event ID 4688
  • Windows PowerShell event IDs 4103 and 4104
  • Sysmon event ID 1

Detected events

  • Suspicious account behavior
    • User creation
    • User added to local/global/universal groups
    • Password guessing (multiple logon failures, one account)
    • Password spraying via failed logon (multiple logon failures, multiple accounts)
    • Password spraying via explicit credentials
    • Bloodhound (admin privileges assigned to the same account with multiple Security IDs)
  • Command line/Sysmon/PowerShell auditing
    • Long command lines
    • Regex searches
    • Obfuscated commands
    • PowerShell launched via WMIC or PsExec
    • PowerShell Net.WebClient Downloadstring
    • Compressed/Base64 encoded commands (with automatic decompression/decoding)
    • Unsigned EXEs or DLLs
  • Service auditing
    • Suspicious service creation
    • Service creation errors
    • Stopping/starting the Windows Event Log service (potential event log manipulation)
  • Mimikatz
    • lsadump::sam
  • EMET & Applocker Blocks

…and more

Examples

Event Command
Event log manipulation .DeepBlue.ps1 .evtxdisablestop-eventlog.evtx
Metasploit native target (security) .DeepBlue.ps1 .evtxmetasploit-psexec-native-target-security.evtx
Metasploit native target (system) .DeepBlue.ps1 .evtxmetasploit-psexec-native-target-system.evtx
Metasploit PowerShell target (security) .DeepBlue.ps1 .evtxmetasploit-psexec-powershell-target-security.evtx
Metasploit PowerShell target (system) .DeepBlue.ps1 .evtxmetasploit-psexec-powershell-target-system.evtx
Mimikatz lsadump::sam .DeepBlue.ps1 .evtxmimikatz-privesc-hashdump.evtx
New user creation .DeepBlue.ps1 .evtxnew-user-security.evtx
Obfuscation (encoding) .DeepBlue.ps1 .evtxPowershell-Invoke-Obfuscation-encoding-menu.evtx
Obfuscation (string) .DeepBlue.ps1 .evtxPowershell-Invoke-Obfuscation-string-menu.evtx
Password guessing .DeepBlue.ps1 .evtxsmb-password-guessing-security.evtx
Password spraying .DeepBlue.ps1 .evtxpassword-spray.evtx
PowerSploit (security) .DeepBlue.ps1 .evtxpowersploit-security.evtx
PowerSploit (system) .DeepBlue.ps1 .evtxpowersploit-system.evtx
PSAttack .DeepBlue.ps1 .evtxpsattack-security.evtx
User added to administrator group .DeepBlue.ps1 .evtxnew-user-security.evtx

Output

DeepBlueCLI outputs in PowerShell objects, allowing a variety of output methods and types, including JSON, HTML, CSV, etc.

For example:

Output Type Syntax
CSV .DeepBlue.ps1 .evtxpsattack-security.evtx | ConvertTo-Csv
Format list (default) .DeepBlue.ps1 .evtxpsattack-security.evtx | Format-List
Format table .DeepBlue.ps1 .evtxpsattack-security.evtx | Format-Table
GridView .DeepBlue.ps1 .evtxpsattack-security.evtx | Out-GridView
HTML .DeepBlue.ps1 .evtxpsattack-security.evtx | ConvertTo-Html
JSON .DeepBlue.ps1 .evtxpsattack-security.evtx | ConvertTo-Json
XML .DeepBlue.ps1 .evtxpsattack-security.evtx | ConvertTo-Xml

Logging setup

Security event 4688 (Command line auditing):

Enable Windows command-line auditing: https://support.microsoft.com/en-us/kb/3004375

Security event 4625 (Failed logons):

Requires auditing logon failures: https://technet.microsoft.com/en-us/library/cc976395.aspx

PowerShell auditing (PowerShell 5.0):

DeepBlueCLI uses module logging (PowerShell event 4103) and script block logging (4104). It does not use transcription.

See: https://www.fireeye.com/blog/threat-research/2016/02/greater_visibilityt.html

To get the PowerShell commandline (and not just script block) on Windows 7 through Windows 8.1, add the following to WindowsSystem32WindowsPowerShellv1.0profile.ps1

$LogCommandHealthEvent = $true
$LogCommandLifecycleEvent = $true

See the following for more information:

Thank you: @heinzarelli and @HackerHurricane

Sysmon

Install Sysmon from Sysinternals: https://docs.microsoft.com/en-us/sysinternals/downloads/sysmon

DeepBlue and DeepWhite currently use Sysmon events, 1, 6 and 7.

Log SHA256 hashes. Others are fine; DeepBlueCLI will use SHA256.

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