These methods can be more difficult to detect but also require a deeper understanding of Windows internals and forensic analysis techniques.

To identify these lesser-known persistence mechanisms, incident responders can use tools like RegRipper for Windows, Autopsy for Linux/MacOS, or Volatility Framework for memory analysis. These tools can help provide valuable insights into the attacker’s tactics and techniques by collecting information about malware persistence mechanisms and other artifacts left behind during an incident.

In terms of avoiding detection, malware developers may use Run Keys in Windows Registry or create scheduled tasks or services that run on a regular basis to maintain access for longer periods of time. However, these methods are well known and often used legitimately, making them less effective for stealthy campaigns. To avoid detection, malware developers may modify system files or create hidden directories in the file system instead.

One lesser-known persistence mechanism is modifying the “sticky keys” feature to execute a command shell before login. This can be done by adding a debugger value for the corresponding registry key using the following command:

// This script adds a debugger value to the registry key for the "sticky keys" feature, allowing for the execution of a command shell before login.

// The REG ADD command is used to add a new registry entry.
REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\sethc.exe" /v Debugger /t REG_SZ /d "cmd /c tasklist"

// The "HKLM" specifies the registry hive, in this case, HKEY_LOCAL_MACHINE.
// The "SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\sethc.exe" specifies the path to the registry key for the "sticky keys" feature.
// The "/v Debugger" specifies the name of the registry value to be added.
// The "/t REG_SZ" specifies the type of the registry value, in this case, a string value.
// The "/d "cmd /c tasklist"" specifies the data to be added to the registry value, in this case, the command "cmd /c tasklist" which will be executed before login.

To test your collection tools, prevention mechanisms in place, and detections, execute this command to trigger the execution of cmd by clicking multiple times on the shift-key on your keyboard.

In terms of response, if you respond to an incident and need to clean up malware persistence as a temporary countermeasure, you can remove the given information using standard OS commands or frameworks like PowerSponse for Windows. In special cases like WMI, cleanup may not be straightforward but is still possible with advanced techniques.

However, it’s essential to note that understanding lesser-known persistence mechanisms isn’t just limited to incident responders. As a developer, having basic knowledge of your environment can help you write scripts and automate tasks that make you more valuable to your manager. Additionally, keeping up with the latest tools and techniques is crucial in today’s fast-paced cybersecurity landscape.

For instance, imagine a situation where your application goes down, and customers are being affected. You can either throw your hands up and say “I have no idea what to do…” or you can SSH into the server, start scanning logs, notice that the diskspace of a particular filesystem is full, and proceed to clean it out. This is a minor example, but I think the point is clear. With that basic knowledge, as a developer, you could write a script that monitors that particular filesystem and cleans it out once it reaches a certain threshold. You have now become that much more valuable to your manager.

Another thing I’ve learned during my career is that things move fast, and if you don’t keep up, you are going to be left behind. The more you know about your entire environment (including the business aspects) the better off you are. That’s not to say you need to be an expert in everything you do, but at least have the knowledge to not be labeled as clueless.