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 CSO newsletter!

Error: Please check your email address.
Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Lucian Constantin

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts