Security researchers link second malware program to rogue printing incidents

The propagation routine of the W32.Printlove worm can cause the printing of useless data, Symantec researchers say

A computer worm that propagates by exploiting a 2010 Windows vulnerability is responsible for some of the recent incidents involving network printers suddenly printing useless data, according to security researchers from Symantec.

Many companies have reported unauthorized printing incidents in recent weeks, prompting antivirus firms to investigate the possible causes.

On June 21, Symantec reported that the rogue printouts were the result of computers being infected with a Trojan program called Trojan.Milicenso.

However, the company's researchers have since determined that the propagation routine of a separate piece of malware, a worm called W32.Printlove, can cause similar problems, Symantec researcher Jeet Morparia said Monday in a blog post.

W32.Printlove infects other computers on the local network by exploiting a remote code execution vulnerability in the Microsoft Windows Print Spooler service that was patched in September 2010. Identified as CVE-2010-2729, this vulnerability was also exploited by the Stuxnet industrial sabotage worm to spread.

The rogue printing behavior can occur when W32.Printlove unsuccessfully attempts to infect a Windows XP computer connected to a shared network printer.

The worm starts by sending a print request to a targeted computer that is specifically crafted to exploit the CVE-2010-2729 vulnerability. If the exploitation attempt is successful, a copy of the malware is dropped in the Windows system directory and then executed.

However, if the system is patched against CVE-2010-2729, a copy of the worm is created in the computer's printer spool directory -- %SystemRoot%\system32\spool\printers -- as a randomly named .spl (Windows Printer Spool) file.

The computer interprets the creation of this file as a new print job and instructs the network printer to print the file's contents, therefore wasting paper and toner.

Because the worm periodically retries to infect a system, the rogue printing behavior will be repeated until all network computers are cleaned, Morparia said. "Tracking down the source of these junk print jobs can be more complicated when there are multiple infections on the network."

Fortunately, the failed infection attempts leave behind .shd files in the printer spool directory that contain details about printing jobs, including the names of computers that initiated them. Administrators can inspect SHD files with a free tool called SPLViewer after shutting down the Print Spooler service, Morparia said.

The W32.Printlove worm might be linked to the previously reported Trojan.Milicenso, Morparia said. "We intend to continue our investigation to confirm any relationship between the two threats."

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

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

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

Learn more >

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

Learn more >

Lexar® JumpDrive® C20c USB Type-C flash drive 

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?