The new update now uses a list of 50,000 domain names for the bots to talk to. Last month a group of technology companies and organizations set up a system to preemptively register the addresses used by Conficker to free systems infected.
This new list makes the current countermeasures put in place last month by Microsoft, Symantec, VeriSign, ICANN and others almost impossible to maintain. The update does show that the Conficker authors are aware of and want to protect their vast Bot Net.
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Vincent Weafer, vice president of Symantec Corp.'s security response group said that the update shows that the hackers want to defend their collection of compromised PCs.
Last month, about 20 technology companies and organizations, including Microsoft, Symantec, VeriSign Inc. and ICANN, the nonprofit group that manages the Internet Domain Name System, joined forces to preemptively register the Internet addresses Conficker's controllers use to maintain their hold on infected machines.
However Conficker.c cranks out a list of 50,000 URLs which could be used by the botnets which makes it hard to .even attempt to register 50,000 domains daily.