By default:

<USERPROFILE>\Documents\PowerShell_transcript.*.txt

However, alternative path, on the local filesystem or on a remote server, can be specified.

Overview

PowerShell Transcript is a mechanism to record a PowerShell console session. The full console input and, depending on the transcript configuration, stdout and stderr streams are logged to a text file. This logging mechanism, disabled by default, is the only Windows built-in feature to gain extended visibility on PowerShell console interactions, and in particular to the results of PowerShell commands entered in a console.

Contrary to Script Block Logging however, PowerShell Transcript does not include content of scripts executed and only the commands as they are entered / typed in the PowerShell console (and thus potentially obfuscated).

PowerShell Transcript is available from PowerShell 2.0 and onward, with a different default file naming convention starting with PowerShell 5.0:

  • Before PowerShell 5.0: PowerShell_transcript.YYYYMMDDHHmmss.txt, with the timestamp being in the system local timezone.

  • Starting with PowerShell 5.0: PowerShell_transcript.<HOSTNAME>.<8_RANDOM_CHAR>.YYYYMMDDHHmmss.txt (with the timestamp also in the system local timezone).

By default, PowerShell Transcript logs will be located directly under a user’s Documents folder (<USERPROFILE>\Documents), with one file per “transcripted” console session. An alternative path, on the local filesystem or on a remote server, can be specified. A number of known paths are referenced in the KAPE target PowerShellTranscripts.

Enabling PowerShell Transcript

PowerShell Transcript can be enabled in a number of ways. By default, only the timestamps of the PowerShell session start and end are logged and an additional configuration is required to log the timestamp of each command execution.

  • For the current PowerShell console session, using the Start-Transcript cmdlet. The IncludeInvocationHeader switch toggles the logging of command execution timestamps. This cmdlet can be added to a user PowerShell profile to be automatically executed upon new PowerShell session. The PowerShell profile can however be trivially bypassed by launching a session with out loading the profile (powershell.exe -NoProfile).

  • Through Group Policy: Computer configuration -> Polices -> Administrative Templates -> Windows Components -> Windows PowerShell -> “Turn on PowerShell Transcription”. As stated in the GPO setting, this is equivalent of calling the Start-Transcript cmdlet for every PowerShell session. The “Include invocation headers” checkbox determine, similarly to the IncludeInvocationHeader switch, wether execution timestamps should be logged for each command.

  • Directly through the registry, by setting the values, under HKLM\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription, EnableTranscripting to 0x1 and EnableInvocationHeader to 0x1 (to enable commands timestamps). While supporting the Start-Transcript cmdlet, PowerShell core does not however appear to take into account these values.

Information of interest

Each PowerShell Transcript is associated with a PowerShell session and include:

  • The user associated with the session.

  • The timestamps of the session start and finish (once the session is closed).

  • The Process ID (PID) of the PowerShell process linked to the session.

  • The PowerShell edition (desktop, core) and version used.

  • Each commands entered / typed in the session, their working directory (as the PowerSehll prompt is logged as well), and their respective stdout and stderr outputs.

  • If enabled, the timestamp of each command execution, in YYYYMMDDHHmmss format and in the system local timezone.

Example of a PowerShell Transcript log file (with command execution timestamps) PowerShell_transcript.HOSTNAME.AZCz+5lm.20240615001946.txt:

**********************
Windows PowerShell transcript start
Start time: 20240615001946
Username: HOSTNAME\USERNAME
RunAs User: HOSTNAME\USERNAME
Configuration Name:
Machine: HOSTNAME (Microsoft Windows NT 10.0.22631.0)
Host Application: C:\WINDOWS\System32\WindowsPowerShell\v1.0\powershell.exe
Process ID: 26208
PSVersion: 5.1.22621.2506
PSEdition: Desktop
PSCompatibleVersions: 1.0, 2.0, 3.0, 4.0, 5.0, 5.1.22621.2506
BuildVersion: 10.0.22621.2506
CLRVersion: 4.0.30319.42000
WSManStackVersion: 3.0
PSRemotingProtocolVersion: 2.3
SerializationVersion: 1.1.0.1
**********************
**********************
Command start time: 20240615001949
**********************
PS C:\Users\USERNAME> whoami
HOSTNAME\USERNAME
**********************
Command start time: 20240615002105
**********************
PS C:\Users\USERNAME> exit
**********************
Windows PowerShell transcript end
End time: 20240615002105
**********************

References

Tags: windows_program_execution windows_powershell_activity

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