Feeds

Conficker zombie botnet drops to 3.5 million

Map of the Problematique

Securing Web Applications Made Simple and Scalable

The "activation" of Windows machines infected with the latest variant of the Conficker worm has allowed security watchers to come up with a far more accurate estimate of how many machines are infected.

Early versions of Conficker called home to 250 different domain names every day to check for updates. Since Wednesday, machines infected by with the latest version of the worm (Conficker-C) began using a sample of 500 out of pre-programmed 50,000 domains a day to search for upgrades.

The unknown virus writers who created the worm are yet to publish any such update, but the call-back behaviour has allowed anti-virus firms to come up with an estimate of how many machines are infected by Conficker-C for the first time.

Vietnamese antivirus firm Bkis reckons 1.3m machines are infected with Conficker-C. A breakdown of infections by country, compiled by Bkis, can be found here. The combined number of computers infected by Conficker A and B is 2.2m, according to Bkis.

That total of around 3.5m is in line with a detailed technical analysis by Conficker which puts the size of the Conficker botnet at between three and four million strong.

IBM's X-Force has a mash-up using Google Maps or Conficker infections across the world, which can be found here. The Conficker Working Group has published more detailed infection maps here.

Estimates of the number of machines ever infected by Conficker vary from ten to 15 million, but these figures ignored disinfections and other factors. It's more meaningful to talk of the current number of zombie drones rather than the number ever infected, because it gives a much better idea of the potential for harm.

As predicted by security watchers beforehand, Conficker's 1 April "activation" passed by without anything happening, much like previous malware trigger dates associated with nuisances such as the Michelangelo virus (1992), CIH (1999), SoBig (2003), and MyDoom (2004). The unknown authors of Conficker didn't publish updates on 1 April, but since infected machines check for updates on a daily basis it would be wrong to think that the threat has passed. Updates using the P2P mechanism built into the worm are also possible.

F-Secure has compiled an updated, informative FAQ on Conficker here, which cover important questions such as how to tell if you're infected and much more besides. Conficker blocks access to security sites, a factor exploited by Joe Stewart of the Conficker Working Group to create a simple test here. ®

The smart choice: opportunity from uncertainty

More from The Register

next story
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
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
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
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.