Ransomware prevents Windows from starting by replacing the master boot record

Ransomware asks users to pay up before letting them start Windows

A new ransomware variant prevents infected computers from loading Windows by replacing their master boot record (MBR) and displays a message asking users for money, according to security researchers from Trend Micro.

"Based on our analysis, this malware copies the original MBR and overwrites it with its own malicious code," said Cris Pantanilla, a threat response engineer at Trend Micro, in a blog post on Thursday. "Right after performing this routine, it automatically restarts the system for the infection take effect."

The MBR is a piece of code that resides in the first sectors of the hard drive and starts the boot loader. The boot loader then loads the OS.

Instead of starting the Windows boot loader, the rogue MBR installed by the new ransomware displays a message that asks users to deposit a sum of money into a particular account via an online payment service called QIWI, in order to receive an unlock code for their computers.

"This code will supposedly resume operating system to load and remove the infection," Pantanilla said. "When the unlock code is used, the MBR routine is removed."

As the name implies, ransomware applications hold something belonging to the victim in ransom until they pay a sum of money. This type of malware is considered the next step in the evolution of scareware, malicious programs that scare users into paying money.

The majority of ransomware applications disable important system functionality or encrypt documents and pictures, but this is the first ransomware program that Trend Micro researchers have seen replacing the MBR to prevent the system from starting.

This represents a serious escalation in ransomware techniques. While users can still run security tools to clean their systems of traditional ransomware applications and even recover some files, if Windows doesn't start at all, like in this case, the remediation procedure becomes much more difficult.

Repairing the MBR is no trivial matter and usually requires booting from the Windows installation disk, getting into the recovery command console and typing special commands.

Ransomware infections are typically more common throughout Eastern Europe and South America, but this type of malware is slowly gaining traction in other regions of the world as well. Some variants that impersonate law enforcement agencies and ask victims to pay fictitious fines have recently been detected in Western Europe.

"Though overshadowed by other more newsworthy threats, ransomware attacks are definitely not out of picture. In fact, this threat appears to be flourishing, as evidenced by the growth of ransomware infections in other parts of Europe," Pantanilla said.

Join the Good Gear Guide newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

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

Essentials

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?