| ID | Technique | Tactic |
|---|---|---|
| T1059.001 | PowerShell | Execution |
| T1059 | Command and Scripting Interpreter | Execution |
| T1562.001 | Disable or Modify Tools | Defense Evasion |
| T1562 | Impair Defenses | Defense Evasion |
Detection: Windows Powershell Import Applocker Policy
Description
The following analytic detects the import of Windows PowerShell Applocker cmdlets, specifically identifying the use of "Import-Module Applocker" and "Set-AppLockerPolicy" with an XML policy. It leverages PowerShell Script Block Logging (EventCode 4104) to capture and analyze script block text. This activity is significant as it may indicate an attempt to enforce restrictive Applocker policies, potentially used by malware like Azorult to disable antivirus products. If confirmed malicious, this could allow an attacker to bypass security controls, leading to further system compromise and persistence.
Search
1`powershell` EventCode=4104 ScriptBlockText="*Import-Module Applocker*" ScriptBlockText="*Set-AppLockerPolicy *" ScriptBlockText="* -XMLPolicy *"
2| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID
3| rename Computer as dest
4| rename UserID as user
5| `security_content_ctime(firstTime)`
6| `security_content_ctime(lastTime)`
7| `windows_powershell_import_applocker_policy_filter`
Data Source
| Name | Platform | Sourcetype | Source |
|---|---|---|---|
| Powershell Script Block Logging 4104 |  Windows |
'xmlwineventlog' |
'XmlWinEventLog:Microsoft-Windows-PowerShell/Operational' |
Macros Used
| Name | Value |
|---|---|
| powershell | (source=WinEventLog:Microsoft-Windows-PowerShell/Operational OR source="XmlWinEventLog:Microsoft-Windows-PowerShell/Operational") |
| windows_powershell_import_applocker_policy_filter | search * |
windows_powershell_import_applocker_policy_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
MITRE ATT&CK
Kill Chain Phases
NIST
CIS
Threat Actors
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
APT19
APT28
APT29
APT3
APT32
APT33
APT38
APT39
APT41
APT5
Aquatic Panda
BRONZE BUTLER
Blue Mockingbird
CURIUM
Chimera
Cinnamon Tempest
Cobalt Group
Confucius
CopyKittens
Daggerfly
DarkHydrus
DarkVishnya
Deep Panda
Dragonfly
Earth Lusca
Ember Bear
FIN10
FIN13
FIN6
FIN7
FIN8
Fox Kitten
GALLIUM
GOLD SOUTHFIELD
Gallmaker
Gamaredon Group
Gorgon Group
HAFNIUM
HEXANE
Inception
Indrik Spider
Kimsuky
Lazarus Group
LazyScripter
Leviathan
Magic Hound
Molerats
MoustachedBouncer
MuddyWater
Mustang Panda
Nomadic Octopus
OilRig
Patchwork
Play
Poseidon Group
RedCurl
Saint Bear
Sandworm Team
Sidewinder
Silence
Stealth Falcon
TA2541
TA459
TA505
TeamTNT
Threat Group-3390
Thrip
ToddyCat
Tonto Team
Turla
Volt Typhoon
WIRTE
Winter Vivern
Wizard Spider
menuPass
APT19
APT32
APT37
APT39
Dragonfly
FIN5
FIN6
FIN7
Fox Kitten
Ke3chang
OilRig
Saint Bear
Stealth Falcon
Whitefly
Windigo
Winter Vivern
Agrius
Aquatic Panda
BRONZE BUTLER
Ember Bear
FIN6
Gamaredon Group
Gorgon Group
INC Ransom
Indrik Spider
Kimsuky
Lazarus Group
Magic Hound
MuddyWater
Play
Putter Panda
Rocke
Saint Bear
TA2541
TA505
TeamTNT
Turla
Wizard Spider
Magic Hound
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
| Setting | Value |
|---|---|
| Disabled | true |
| Cron Schedule | 0 * * * * |
| Earliest Time | -70m@m |
| Latest Time | -10m@m |
| Schedule Window | auto |
| Creates Notable | Yes |
| Rule Title | %name% |
| Rule Description | %description% |
| Notable Event Fields | user, dest |
| Creates Risk Event | True |
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.
Implementation
To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
Known False Positives
administrators may execute this command that may cause some false positive.
Associated Analytic Story
Risk Based Analytics (RBA)
| Risk Message | Risk Score | Impact | Confidence |
|---|---|---|---|
| A PowerShell script contains Import Applocker Policy command $ScriptBlockText$ with EventCode $EventCode$ on host $dest$ | 49 | 70 | 70 |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
References
Detection Testing
| Test Type | Status | Dataset | Source | Sourcetype |
|---|---|---|---|---|
| Validation | ✅ Passing | N/A | N/A | N/A |
| Unit | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-PowerShell/Operational |
XmlWinEventLog |
| Integration | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-PowerShell/Operational |
XmlWinEventLog |
Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
Source: GitHub | Version: 3