Software Installation

A subject can install unapproved browser extensions that provide additional features and functionality to the browser.

A subject can install an unapproved browser with features that frustrate or prevent preventions or detections, such as built-in VPN, Tor access, or automatic browser artifact destruction.

A subject can install an unapproved cloud storage application that has the ability to sync files across the Internet.

A subject installs a File Transfer Protocol (FTP) client which can be used to access FTP servers across the a network.

A subject installs an unapproved messenger application with the ability to transmit data and/or files across the Internet.

A subject installs an unapproved note taking application with the ability to sync notes across the Internet.

A subject installs a Remote Desktop Protocol (RDP) client which can be used to access RDP servers across a network.

A subject installs screen sharing software which can be used to capture images or other information from a target system.

A subject installs a Secure Shell (SSH) client, which can be used to access SSH servers across a network.

A subject installs a hypervisor that allows them to create and access virtual environments on a device.

A subject installs a VPN application that allows them to tunnel their traffic.

By only allowing pre-approved software to be installed and run on corporate devices, the subject is unable to install software themselves.

The Debian Package Management (dpkg) utility is responsible for software installation and management. This tool provides one or more log files, located at /var/log/dpkg.log.

This log contains the timestamp, the action conducted, and the package name and version.

To view pakage installs, the following command can be used: grep “ install ” /var/log/dpkg.log*

To view package uninstalls, the following command can be used: grep “ remove ” /var/log/dpkg.log*

This detection is not enabled by default and requires additional configuration.

System Monitor (Sysmon) Event ID 1 is used to record process execution. Reviewing these logs can determine what software has been run on a system.

Windows Jump Lists are a feature that provides quick access to recently or frequently used files.

LNK files or Shortcut files are stored in the location C:\Users\<user>\AppData\Roaming\Microsoft\Windows\Recent Items and have the “.lnk” file extension.

These files are automatically created when a user account accesses a file through Windows Explorer.

This artifact can provide information as to when a file was accessed, modified, and created, the file path and name, and the file size. .LNK files persist even if the actual file has been deleted, helping to uncover if a file has been accessed then subsequently deleted or moved as it is no longer present in the recorded full file path.

In modern versions of the Windows operating system, the prefetch feature serves an important function in speeding up the run time of applications. It does this by creating a cache of information on an application on its first run that is is stored for later reference in c:\windows\prefetch, these files are created with the extension .pf and have the following format <EXECUTABLE>-<HASH>.pf.

These created files contain the created and modified timestamps of the respective file, the file size, process path, how many times it has been run, the last time it was run, and resources it references in the first 10 seconds of execution.

Since every executable that is run will have a prefetch file created when the feature is enabled, the prefetch directory and the contents within it can offer new and valuable insights during an investigation, particularly when the original executable no longer exists.