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Microsoft-Windows-PowerShell › Event 4104

Event ID 4104 — Creating Scriptblock text (MessageNumber of MessageTotal).

Provider
Microsoft-Windows-PowerShell
Channel
Operational
Level
Verbose
Collection Priority
Recommended (Yamato Security, others)
Task
StartingCommand
Opcode
Oncreatecalls

Description

Creating Scriptblock text (MessageNumber of MessageTotal).

Message #

Creating Scriptblock text (%1 of %2):
%3

ScriptBlock ID: %4
Path: %5

Fields #

NameDescription
MessageNumber Int32Part number of the current script block fragment (large scripts are split across multiple events)
MessageTotal Int32Total number of script block fragments for the complete script
ScriptBlockText UnicodeStringContent of the executed PowerShell script block
ScriptBlockId UnicodeStringScriptBlock ID.
Path UnicodeStringFull path to the executed script file

Example Event #

{
  "system": {
    "provider": "Microsoft-Windows-PowerShell",
    "guid": "A0C1853B-5C40-4B15-8766-3CF1C58F985A",
    "event_source_name": "",
    "event_id": 4104,
    "version": 1,
    "level": 5,
    "task": 2,
    "opcode": 15,
    "keywords": 0,
    "time_created": "2023-11-06T01:35:05.990326+00:00",
    "event_record_id": 901,
    "correlation": {
      "ActivityID": "E4DB489E-1037-0002-FA44-ECE43710DA01"
    },
    "execution": {
      "process_id": 15468,
      "thread_id": 15184
    },
    "channel": "Microsoft-Windows-PowerShell/Operational",
    "computer": "WinDev2310Eval",
    "security": {
      "user_id": "S-1-5-21-1992711665-1655669231-58201500-1000"
    }
  },
  "event_data": {
    "MessageNumber": 1,
    "MessageTotal": 1,
    "ScriptBlockText": "prompt",
    "ScriptBlockId": "6baf0dc7-a83f-43e1-bb6a-d7ab8d05eeb0",
    "Path": ""
  },
  "message": ""
}

Detection Patterns #

Detection Rules #

View all rules referencing this event →

Sigma # view in reference

  • AADInternals PowerShell Cmdlets Execution - PsScript source high: Detects ADDInternals Cmdlet execution. A tool for administering Azure AD and Office 365. Which can be abused by threat actors to attack Azure AD or Office 365.
  • Access to Browser Login Data source medium: Adversaries may acquire credentials from web browsers by reading files specific to the target browser. Web browsers commonly save credentials such as website usernames and passwords so that they do not need to be entered manually in the future. Web browsers typically store the credentials in an encrypted format within a credential store.
  • Potential Active Directory Enumeration Using AD Module - PsScript source medium: Detects usage of the "Import-Module" cmdlet to load the "Microsoft.ActiveDirectory.Management.dl" DLL. Which is often used by attackers to perform AD enumeration.
Show 17 more (162 total)

Elastic # view in reference

Show 9 more (12 total)
  • Potential PowerShell Obfuscation via Concatenated Dynamic Command Invocation source high: Detects PowerShell scripts that builds commands from concatenated string literals inside dynamic invocation constructs like &() or .(). Attackers use concatenated dynamic invocation to obscure execution intent, bypass keyword-based detections, and evade AMSI.
  • Potential PowerShell Obfuscation via High Numeric Character Proportion source low: Detects long PowerShell script block content with unusually high numeric character density (high digit-to-length ratio), often produced by byte arrays, character-code reconstruction, or embedded encoded blobs. Attackers use numeric-heavy obfuscation to conceal payloads and rebuild them at runtime to avoid static inspection.
  • Potential Dynamic IEX Reconstruction via Environment Variables source medium: Detects PowerShell scripts that reconstructs IEX (Invoke-Expression) by indexing environment variable strings (for example, $env:VAR[1,2,3]) or related `.name[...]` slices and joining characters at runtime. Attackers use environment-variable slicing to hide dynamic execution and evade keyword-based detections and AMSI.
  • Dynamic IEX Reconstruction via Method String Access source low: Detects PowerShell scripts that rebuilds IEX by converting method references to strings (for example, ''.IndexOf.ToString()) and extracting multiple indexed characters (for example, [n,n,n]). Attackers use method-string reconstruction to conceal dynamic execution and bypass static detections and AMSI.
  • PowerShell Obfuscation via Negative Index String Reversal source low: Detects PowerShell scripts that uses negative index ranges (for example, $var[-1..0]) to reverse strings or arrays and rebuild content at runtime. Attackers use index reversal to reconstruct hidden commands or payloads and evade static analysis and AMSI.
  • Potential PowerShell Obfuscation via Reverse Keywords source low: Detects PowerShell scripts containing reversed keyword strings associated with execution or network activity (for example, ekovni, noisserpxe, daolnwod, tcejbo-wen, tcejboimw, etc.). Attackers reverse keywords and reconstruct them at runtime to hide intent and evade static detection and AMSI.
  • Potential PowerShell Obfuscation via String Concatenation source high: Detects PowerShell scripts that repeatedly concatenates multiple quoted string literals with + to assemble commands or tokens at runtime. Attackers use string concatenation to fragment keywords or URLs and evade static analysis and AMSI.
  • Potential PowerShell Obfuscation via String Reordering source medium: Detects PowerShell scripts that uses format placeholders like "{0}{1}" with the -f operator or ::Format to reorder strings at runtime. Attackers use format-based reconstruction to hide commands or payload strings and evade static analysis and AMSI.
  • Potential PowerShell Obfuscation via Special Character Overuse source medium: Detects PowerShell scripts dominated by whitespace and special characters with low symbol diversity, a profile often produced by formatting or encoding obfuscation. Attackers use symbol-heavy encoding or formatting (for example, SecureString-style blobs or character-level transforms) to hide payloads and evade static analysis and AMSI.

Splunk # view in reference

  • AdsiSearcher Account Discovery source: The following analytic detects the use of the `[Adsisearcher]` type accelerator in PowerShell to query Active Directory for domain users. It leverages PowerShell Script Block Logging (EventCode=4104) to identify script blocks containing `[adsisearcher]`, `objectcategory=user`, and `.findAll()`. This activity is significant as it may indicate an attempt by adversaries or Red Teams to enumerate domain users for situational awareness and Active Directory discovery. If confirmed malicious, this could lead to further reconnaissance, privilege escalation, or lateral movement within the network.
  • Allow Inbound Traffic In Firewall Rule source: The following analytic detects a suspicious PowerShell command that allows inbound traffic to a specific local port within the public profile. It leverages PowerShell script block logging (EventCode 4104) to identify commands containing keywords like "firewall," "Inbound," "Allow," and "-LocalPort." This activity is significant because it may indicate an attacker attempting to establish remote access by modifying firewall rules. If confirmed malicious, this could allow unauthorized access to the machine, potentially leading to further exploitation and data exfiltration.
  • Delete ShadowCopy With PowerShell source: The following analytic detects the use of PowerShell to delete shadow copies via the WMIC PowerShell module. It leverages EventCode 4104 and searches for specific keywords like "ShadowCopy," "Delete," or "Remove" within the ScriptBlockText. This activity is significant because deleting shadow copies is a common tactic used by ransomware, such as DarkSide, to prevent data recovery. If confirmed malicious, this action could lead to irreversible data loss and hinder recovery efforts, significantly impacting business continuity and data integrity.
Show 17 more (109 total)
  • Detect Certify With PowerShell Script Block Logging source: The following analytic detects the use of the Certify tool via an in-memory PowerShell function to enumerate Active Directory Certificate Services (AD CS) environments. It leverages PowerShell Script Block Logging (EventCode 4104) to identify specific command patterns associated with Certify's enumeration and exploitation functions. This activity is significant as it indicates potential reconnaissance or exploitation attempts against AD CS, which could lead to unauthorized certificate issuance. If confirmed malicious, attackers could leverage this to escalate privileges, persist in the environment, or access sensitive information by abusing AD CS.
  • Detect Copy of ShadowCopy with Script Block Logging source: The following analytic detects the use of PowerShell commands to copy the SAM, SYSTEM, or SECURITY hives, which are critical for credential theft. It leverages PowerShell Script Block Logging (EventCode=4104) to capture and analyze the full command executed. This activity is significant as it indicates an attempt to exfiltrate sensitive registry hives for offline password cracking. If confirmed malicious, this could lead to unauthorized access to credentials, enabling further compromise of the system and potential lateral movement within the network.
  • Detect Empire with PowerShell Script Block Logging source: The following analytic detects suspicious PowerShell execution indicative of PowerShell-Empire activity. It leverages PowerShell Script Block Logging (EventCode=4104) to capture and analyze commands sent to PowerShell, specifically looking for patterns involving `system.net.webclient` and base64 encoding. This behavior is significant as it often represents initial stagers used by PowerShell-Empire, a known post-exploitation framework. If confirmed malicious, this activity could allow attackers to download and execute additional payloads, leading to potential code execution, data exfiltration, or further compromise of the affected system.
  • Detect Mimikatz With PowerShell Script Block Logging source: The following analytic detects the execution of Mimikatz commands via PowerShell by leveraging PowerShell Script Block Logging (EventCode=4104). This method captures and logs the full command sent to PowerShell, allowing for the identification of suspicious activities such as Pass the Ticket, Pass the Hash, and credential dumping. This activity is significant as Mimikatz is a well-known tool used for credential theft and lateral movement. If confirmed malicious, this could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information within the environment.
  • Disabled Kerberos Pre-Authentication Discovery With Get-ADUser source: The following analytic detects the execution of the `Get-ADUser` PowerShell cmdlet with parameters indicating a search for domain accounts with Kerberos Pre-Authentication disabled. It leverages PowerShell Script Block Logging (EventCode=4104) to identify this specific activity. This behavior is significant because discovering accounts with Kerberos Pre-Authentication disabled can allow adversaries to perform offline password cracking. If confirmed malicious, this activity could lead to unauthorized access to user accounts, potentially compromising sensitive information and escalating privileges within the network.
  • Disabled Kerberos Pre-Authentication Discovery With PowerView source: The following analytic detects the execution of the `Get-DomainUser` commandlet with the `-PreauthNotRequired` parameter using PowerShell Script Block Logging (EventCode=4104). This command is part of PowerView, a tool used for enumerating Windows Active Directory networks. Identifying domain accounts with Kerberos Pre-Authentication disabled is significant because adversaries can leverage this information to attempt offline password cracking. If confirmed malicious, this activity could lead to unauthorized access to domain accounts, potentially compromising sensitive information and escalating privileges within the network.
  • Domain Group Discovery with Adsisearcher source: The following analytic detects the use of the `[Adsisearcher]` type accelerator in PowerShell to query Active Directory for domain groups. It leverages PowerShell Script Block Logging (EventCode=4104) to identify specific script blocks containing `[adsisearcher]` and group-related queries. This activity is significant as it may indicate an attempt by adversaries or Red Teams to enumerate domain groups for situational awareness and Active Directory discovery. If confirmed malicious, this behavior could lead to further reconnaissance, privilege escalation, or lateral movement within the network.
  • Elevated Group Discovery with PowerView source: The following analytic detects the execution of the `Get-DomainGroupMember` cmdlet from PowerView, identified through PowerShell Script Block Logging (EventCode=4104). This cmdlet is used to enumerate members of elevated domain groups such as Domain Admins and Enterprise Admins. Monitoring this activity is crucial as it indicates potential reconnaissance efforts by adversaries to identify high-privileged users within the domain. If confirmed malicious, this activity could lead to targeted attacks on privileged accounts, facilitating further compromise and lateral movement within the network.
  • Exchange PowerShell Module Usage source: The following analytic detects the usage of specific Exchange PowerShell modules, such as New-MailboxExportRequest, New-ManagementRoleAssignment, New-MailboxSearch, and Get-Recipient. It leverages PowerShell Script Block Logging (EventCode 4104) to identify these commands. This activity is significant because these modules can be exploited by adversaries who have gained access via ProxyShell or ProxyNotShell vulnerabilities. If confirmed malicious, attackers could export mailbox contents, assign management roles, conduct mailbox searches, or view recipient objects, potentially leading to data exfiltration, privilege escalation, or unauthorized access to sensitive information.
  • Get ADDefaultDomainPasswordPolicy with Powershell Script Block source: The following analytic detects the execution of the `Get-ADDefaultDomainPasswordPolicy` PowerShell cmdlet, which is used to retrieve the password policy in a Windows domain. This detection leverages PowerShell Script Block Logging (EventCode=4104) to identify the specific command execution. Monitoring this activity is significant as it can indicate an attempt to gather domain policy information, which is often a precursor to further malicious actions. If confirmed malicious, this activity could allow an attacker to understand password policies, aiding in password attacks or further domain enumeration.
  • Get ADUser with PowerShell Script Block source: The following analytic detects the execution of the `Get-AdUser` PowerShell cmdlet, which is used to enumerate all domain users. It leverages PowerShell Script Block Logging (EventCode=4104) to identify instances where this command is executed with a filter. This activity is significant as it may indicate an attempt by adversaries or Red Teams to gather information about domain users for situational awareness and Active Directory discovery. If confirmed malicious, this behavior could lead to further reconnaissance and potential exploitation of user accounts within the domain.
  • Get ADUserResultantPasswordPolicy with Powershell Script Block source: The following analytic detects the execution of the `Get-ADUserResultantPasswordPolicy` PowerShell cmdlet, which is used to obtain the password policy in a Windows domain. It leverages PowerShell Script Block Logging (EventCode=4104) to identify this activity. Monitoring this behavior is significant as it may indicate an attempt to enumerate domain policies, a common tactic used by adversaries for situational awareness and Active Directory discovery. If confirmed malicious, this activity could allow attackers to understand password policies, aiding in further attacks such as password guessing or policy exploitation.
  • Get DomainPolicy with Powershell Script Block source: The following analytic detects the execution of the `Get-DomainPolicy` cmdlet using PowerShell Script Block Logging (EventCode=4104). It leverages logs capturing script block text to identify attempts to obtain the password policy in a Windows domain. This activity is significant as it indicates potential reconnaissance efforts by adversaries or Red Teams to gather domain policy information, which is crucial for planning further attacks. If confirmed malicious, this behavior could lead to detailed knowledge of domain security settings, aiding in privilege escalation or lateral movement within the network.
  • Get-DomainTrust with PowerShell Script Block source: The following analytic detects the execution of the Get-DomainTrust command from PowerView using PowerShell Script Block Logging (EventCode=4104). This method captures the full command sent to PowerShell, allowing for detailed inspection. Identifying this activity is significant because it may indicate an attempt to gather domain trust information, which is often a precursor to lateral movement or privilege escalation. If confirmed malicious, this activity could enable an attacker to map trust relationships within the domain, potentially leading to further exploitation and compromise of additional systems.
  • Get DomainUser with PowerShell Script Block source: The following analytic detects the execution of the `Get-DomainUser` cmdlet using PowerShell Script Block Logging (EventCode=4104). This cmdlet is part of PowerView, a tool often used for domain enumeration. The detection leverages PowerShell operational logs to identify instances where this command is executed. Monitoring this activity is crucial as it may indicate an adversary's attempt to gather information about domain users, which is a common step in Active Directory Discovery. If confirmed malicious, this activity could lead to further reconnaissance and potential exploitation of domain resources.
  • Get-ForestTrust with PowerShell Script Block source: The following analytic detects the execution of the Get-ForestTrust command from PowerSploit using PowerShell Script Block Logging (EventCode=4104). This method captures the full command sent to PowerShell, providing detailed visibility into potentially suspicious activities. Monitoring this behavior is crucial as it can indicate an attempt to gather domain trust information, which is often a precursor to lateral movement or privilege escalation. If confirmed malicious, this activity could allow an attacker to map trust relationships within the domain, facilitating further exploitation and access to sensitive resources.
  • Get WMIObject Group Discovery with Script Block Logging source: The following analytic detects the execution of the `Get-WMIObject Win32_Group` command using PowerShell Script Block Logging (EventCode=4104). This method captures the full command sent to PowerShell, allowing for detailed analysis. Identifying group information on an endpoint is not inherently malicious but can be suspicious based on context such as time, endpoint, and user. This activity is significant as it may indicate reconnaissance efforts by an attacker. If confirmed malicious, it could lead to further enumeration and potential lateral movement within the network.

References #