Ransomware attacks have become increasingly sophisticated, leveraging every tool at their disposal to wreak havoc. Among these tools, scripting languages like PowerShell, batch scripts, JavaScript, and Visual Basic scripting have become favorites for attackers. These languages are powerful and versatile, making them ideal for automating tasks, but in the wrong hands, they can be used to execute some pretty nasty stuff.
PowerShell: A Double-Edged Sword
PowerShell is a powerhouse in the world of scripting. It's like the Swiss Army knife of Windows, capable of doing almost anything from managing files to interacting with the Win32 API and .NET framework assemblies. This flexibility is a boon for system administrators, but it also makes PowerShell an attractive tool for cybercriminals.
Why Ransomware Loves PowerShell:
Post-Exploitation Frameworks: Tools like Empire and PowerSploit are written in PowerShell, allowing attackers to execute a wide range of post-exploitation activities.
Obfuscation: Daniel Bohannon’s Invoke-Obfuscation project makes it easy to hide malicious PowerShell commands. Combine this with his DOSfuscation techniques, and you’ve got a recipe for highly obfuscated, hard-to-detect scripts.
Elastic Syntax: PowerShell’s flexible parameter syntax means attackers can shorten commands, making them less obvious in logs. For example, instead of using -ExecutionPolicy Unrestricted, an attacker might just use -ex Unrestricted.
PowerShell Logging:
Tracking PowerShell Misuse:
PowerShell isn’t just powerful for attackers; it’s also great for defenders. For example, the PSReadLine module in PowerShell keeps a history of commands for each user. This can be a goldmine when investigating an attack, especially if the attacker’s credentials are captured in the history.
You can find these history files at: %APPDATA%\Microsoft\Windows\PowerShell\PSReadLine\ConsoleHost_history.txtBatch Scripts: The Silent Executors
Batch scripts might seem old school, but they’re still a favorite among ransomware authors. These .bat files can be incredibly sneaky, often executing without leaving much of a trace.
What Makes Batch Scripts Dangerous:
Lack of Default Logging: By default, Windows doesn’t log batch script execution. This means that unless you’ve enabled process auditing or have an EDR solution in place, you might not even know a script has run.
Self-Destruction: Batch scripts can delete themselves after execution, making it harder to track what happened. Imagine a PE file dropping a batch script that deletes the original file and then itself—tricky to trace, right?
Where to Look:
Keep an eye on Shimcache, where batch files might leave a trace even after they’ve deleted themselves.
JavaScript and Visual Basic: Not Just for the Web
Most people think of JavaScript as the language of the web, but did you know that Microsoft’s Windows Script Host (WSH) can also run JavaScript on your local machine? This is done through wscript.exe, which executes .js files.
How Attackers Use JavaScript:
Direct Execution: Attackers can run JavaScript files directly using the CLI version of WSH (cscript.exe), making it easy to execute scripts with a double-click.
Obfuscation and Malicious Code: Just like PowerShell, JavaScript can be obfuscated to hide malicious intent. Attackers often use this to bypass detection mechanisms.
Learn more about Microsoft’s JScript at https://en.wikipedia.org/wiki/JScript.Learn more about ECMAScript at
https://en.wikipedia.org/wiki/ECMAScript.Conclusion: Staying One Step Ahead
Ransomware isn’t going away anytime soon, and as defenders, we need to stay vigilant. By understanding how scripting engines are abused, we can better prepare ourselves to detect and respond to these threats. Whether it’s through enabling logging, monitoring specific directories, or simply staying informed, every little bit helps in the fight against ransomware.
So, the next time you see a suspicious script running on your network, don’t brush it off. It might just be the tip of the iceberg.
Akash Patel
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