New ransomware abuses Windows PowerShell, Word document macros

The PowerWare ransomware is written completely in the Windows PowerShell scripting language

A new ransomware program written in Windows PowerShell is being used in attacks against enterprises, including health care organizations, researchers warn.

PowerShell is a task automation and configuration management framework that's included in Windows and is commonly used by systems administrators. It has its own powerful scripting language that has been used to create sophisticated malware in the past.

The new ransomware program, dubbed PowerWare, was discovered by researchers from security firm Carbon Black and is being distributed to victims via phishing emails containing Word documents with malicious macros, an increasingly common attack technique.

The Carbon Black team found PowerWare when it targeted one of its customers: an unnamed healthcare organization. Multiple hospitals have recently fallen victim to ransomware attacks.

The malicious Word documents masqueraded as an invoice, the Carbon Black researchers said. When opened, it instructed users to enable Word editing and content, claiming that these actions were necessary to view the files.

In reality, enabling editing disables Microsoft Word's "preview" sandbox and enabling content allows the execution of the embedded macro code, which Office blocks by default.

If the malicious macro code is allowed to run, it opens the Windows command line (cmd.exe) and launches two instances of PowerShell (powershell.exe). One instance downloads the PowerWare ransomware from a remote server in the form of a PowerShell script and the other instance executes the script.

After this point, the infection routine is similar to that of other ransomware programs: The script generates an encryption key; uses it to encrypt files with specific extensions, including documents, pictures, videos, archives and source code; sends the key to the attackers' server and generates the ransom note in the form of an HTML file.

Based on the payment instructions, the attackers use the Tor anonymity network to hide their command-and-control server. The initial ransom is $500, but it goes up to $1,000 after a couple of weeks.

PowerWare is not the first ransomware implementation in PowerShell. Security researchers from Sophos found a similar Russian-language ransomware program back in 2013. Then in 2015, they found another one that used the "Los Pollos Hermanos" logo from the Breaking Bad TV show.

While PowerShell-based malware is not new, its use has increased in recent months and it is arguably harder to detect than traditional malware because of PowerShell's legitimate use and popularity, especially in enterprise environments.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Matthew Stivala

HP OfficeJet 250 Mobile Printer

The HP OfficeJet 250 Mobile Printer is a great device that fits perfectly into my fast paced and mobile lifestyle. My first impression of the printer itself was how incredibly compact and sleek the device was.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?