Feeds

Mutant son of MyDoom plans three-pronged attack

Multiple vulns exploited, end of world nigh

  • alert
  • submit to reddit

Using blade systems to cut costs and sharpen efficiencies

Virus writers have used code from the infamous Mydoom worm to create a potentially dangerous new Internet worm which uses multiple methods to spread.

Plexus-A spreads using three different methods: infected email attachments, file-sharing networks and Windows vulnerabilities (the LSASS vulnerability used by Sasser and the RPC DCOM flaw used by Blaster). The as yet unknown virus authors used MyDoom source code as the basis for creating Plexus, according to an analysis of the worm by Russian AV firm Kaspersky Labs.

David Emm, senior technology consultant at Kaspersky Labs, said that the multiple spreading methods is helping Plexus to infect more machines. No worm since Nimda has used as many methods to spread, according to Emm. Kaspersky rates Plexus as a moderate risk. It is spreading - but nothing like as fast as Sasser or Blaster - and the main concern about the worm stems from the fact it creates a backdoor for hackers on infected machines. These compromised machines could be used for spam runs or as a platform for DDoS attacks. However the motives of the virus authors behind the worm remain unclear.

Plexus-A chooses from five different email message headers in an attempt to bamboozle users. Each message has a different header, body and attachment name. The only characteristic which does not change is the file size: 16208 bytes when compressed with FSG and 57856 when uncompressed. Mac and Linux users are - as usual - immune but Plexus is a menace for Windows users.

Upon execution Plexus-A copies itself to the Windows system registry under the name upu.exe, which runs every time a machine is rebooted after infection. Plexus sends copies of itself to email addresses harvested from the hard drives of infected machines.

The worm is among the first to specifically target users of Kaspersky Labs' AV software. Plexus' payload includes attempts to prevent downloads of Kaspersky Anti-Virus database updates. Plexus also scans the Net for systems vulnerable to the flaws it exploits. The worm opens a backdoor onto infected machines on port 1250, making it possible for files to be remotely uploaded to and from the victim machine. The open port leaves the victim machine vulnerable to further attacks, Kaspersky Labs warns.

Users are advised patch Windows boxes, update anti-virus signature files and use firewalls to shelter against Plexus and similar irritants that are doubtless just around the corner. Is there no end to this viral madness? ®

Related stories

Windows worms tax ISPs
Sasser worm creates havoc
Sasser creates European pandemonium
German police arrest Sasser worm suspect
Sasser ups cost of Windows - Gartner
Phatbot arrest throws open trade in zombie PCs
Blaster rewrites Windows worm rules

The smart choice: opportunity from uncertainty

More from The Register

next story
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
NEW, SINISTER web tracking tech fingerprints your computer by making it draw
Have you been on YouPorn lately, perhaps? White House website?
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Black Hat anti-Tor talk smashed by lawyers' wrecking ball
Unmasking hidden users is too hot for Carnegie-Mellon
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
Own a Cisco modem or wireless gateway? It might be owned by someone else, too
Remote code exec in HTTP server hands kit to bad guys
prev story

Whitepapers

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.