Skip to content

Latest commit

 

History

History
56 lines (35 loc) · 2.23 KB

T1148.md

File metadata and controls

56 lines (35 loc) · 2.23 KB

T1148 - HISTCONTROL

The HISTCONTROL environment variable keeps track of what should be saved by the history command and eventually into the ~/.bash_history file when a user logs out. This setting can be configured to ignore commands that start with a space by simply setting it to "ignorespace". HISTCONTROL 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. HISTCONTROL does not exist by default on macOS, but can be set by the user and will be respected. Adversaries can use this to operate without leaving traces by simply prepending a space to all of their terminal commands.

Detection: Correlating a user session with a distinct lack of new commands in their .bash_history can be a clue to suspicious behavior. Additionally, users checking or changing their HISTCONTROL environment variable is also suspicious.

Platforms: Linux, macOS

Data Sources: Process Monitoring, Authentication logs, File monitoring, Environment variable

Defense Bypassed: Log analysis, Host forensic analysis

Permissions Required: User

Atomic Tests


Atomic Test #1 - Disable history collection

Disables history collection in shells

Supported Platforms: Linux, macOS

Inputs

Name Description Type Default Value
evil_command Command to run after shell history collection is disabled String whoami

Run it with sh!

export HISTCONTROL=ignoreboth
ls #{evil_command}


Atomic Test #2 - Mac HISTCONTROL

xxx

Supported Platforms: macOS, Linux

Run it with these steps!

  1. export HISTCONTROL=ignoreboth
  2. echo export "HISTCONTROL=ignoreboth" >> ~/.bash_profile
  3. ls
  4. whoami > recon.txt