Adversaries may impair command history logging to hide commands they run on a compromised system. Various command interpreters keep track of the commands users type in their terminal so that users can retrace what they've done.
On Linux and macOS, command history is tracked in a file pointed to by the environment variable <code>HISTFILE</code>. When a user logs off a system, this information is flushed to a file in the user's home directory called <code>~/.bash_history</code>. The <code>HISTCONTROL</code> environment variable keeps track of what should be saved by the <code>history</code> command and eventually into the <code>~/.bash_history</code> file when a user logs out. <code>HISTCONTROL</code> does not exist by default on macOS, but can be set by the user and will be respected.
Adversaries may clear the history environment variable (<code>unset HISTFILE</code>) or set the command history size to zero (<code>export HISTFILESIZE=0</code>) to prevent logging of commands. Additionally, <code>HISTCONTROL</code> can be configured to ignore commands that start with a space by simply setting it to "ignorespace". <code>HISTCONTROL</code> can also be set to ignore duplicate commands by setting it to "ignoredups". In some Linux systems, this is set by default to "ignoreboth" which covers both of the previous examples. This means that “ ls” will not be saved, but “ls” would be saved by history. Adversaries can abuse this to operate without leaving traces by simply prepending a space to all of their terminal commands.
On Windows systems, the <code>PSReadLine</code> module tracks commands used in all PowerShell sessions and writes them to a file (<code>$env:APPDATA\Microsoft\Windows\PowerShell\PSReadLine\ConsoleHost_history.txt</code> by default). Adversaries may change where these logs are saved using <code>Set-PSReadLineOption -HistorySavePath {File Path}</code>. This will cause <code>ConsoleHost_history.txt</code> to stop receiving logs. Additionally, it is possible to turn off logging to this file using the PowerShell command <code>Set-PSReadlineOption -HistorySaveStyle SaveNothing</code>.(Citation: Microsoft PowerShell Command History)(Citation: Sophos PowerShell command audit)(Citation: Sophos PowerShell Command History Forensics)
Adversaries may also leverage a Network Device CLI on network devices to disable historical command logging (e.g. <code>no logging</code>).
View in MITRE ATT&CK®| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| PR.PS-01.01 | Configuration baselines | Mitigates | T1562.003 | Impair Command History Logging |
Comments
This diagnostic statement provides for securely configuring production systems. This includes hardening default configurations and making security-focused setting adjustments to reduce the attack surface, enforce best practices, and protect sensitive data thereby mitigating adversary exploitation.
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| PR.PS-01.02 | Least functionality | Mitigates | T1562.003 | Impair Command History Logging |
Comments
This diagnostic statement provides for limiting unnecessary software, services, ports, protocols, etc. Ensuring systems only have installed and enabled what is essential for their operation reduces the attack surface and minimizes vulnerabilities, which mitigates a wide range of techniques.
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| PR.PS-01.03 | Configuration deviation | Mitigates | T1562.003 | Impair Command History Logging |
Comments
This diagnostic statement provides protection from Impair Defenses: Impair Command History Logging through the implementation of security configuration baselines for OS, software, file integrity monitoring and imaging. Security baseline configuration of the Operating System and integrity checking can help protect against adversaries attempting to compromise and modify software and its configurations.
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| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| CM-06 | Configuration Settings | mitigates | T1562.003 | Impair Command History Logging | |
| CM-02 | Baseline Configuration | mitigates | T1562.003 | Impair Command History Logging | |
| CM-07 | Least Functionality | mitigates | T1562.003 | Impair Command History Logging | |
| SI-04 | System Monitoring | mitigates | T1562.003 | Impair Command History Logging |
| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| action.hacking.variety.Disable controls | Disable or interfere with security controls | related-to | T1562.003 | Impair Command History Logging | |
| action.malware.variety.Disable controls | Disable or interfere with security controls | related-to | T1562.003 | Impair Command History Logging |
| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| amazon_inspector | Amazon Inspector | technique_scores | T1562.003 | Impair Command History Logging |
Comments
The Amazon Inspector Best Practices assessment package can assess security control "Configure permissions for system directories" that prevents privilege escalation by local users and ensures only the root account can modify/execute system configuration information and binaries. Amazon Inspector does not directly protect against system modifications rather it just checks to see if security controls are in place which can inform decisions around hardening the system. Due to this and the fact the security control is only supported for Linux platforms, the score is Minimal.
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