FBI takes down coreflood botnet (after 8 years in operation?)

Discussion in 'Anti-Virus' started by Virus Guy, May 6, 2011.

  1. Virus Guy

    Virus Guy Guest

    Is this the same "coreflood" that's been around since 2002?

    Controlled by the same people?



    Court order cripples Coreflood botnet, says FBI

    But Microsoft re-releases Coreflood scrubber

    By Gregg Keizer
    April 26, 2011 04:32 PM ET

    Computerworld - Although the Federal Bureau of Investigation (FBI) said
    a federal temporary restraining order has crippled the Coreflood botnet
    in the U.S., Microsoft today took the unusual step of pushing a second
    version of its monthly malware cleaner to Windows users to again quash
    the botnet.

    Coreflood made the news earlier this month when the U.S. Department of
    Justice (DOJ) and FBI obtained an unprecedented temporary restraining
    order that allowed them to seize command-and-control servers that
    managed the botnet's estimated 2.3 million compromised PCs.

    Those servers were replaced by government-controlled systems.

    The court order also allowed the DOJ and FBI to issue commands using
    those replacement servers that disabled, but did not uninstall,
    Coreflood on infected PCs that asked for new commands.

    In an affidavit filed in a Connecticut federal court last Saturday, FBI
    Special Agent Briana Neumiller said that the server seizure and
    "kill-switch" instructions issued to the malware have crippled the

    On April 13, the day after the DOJ and FBI seized the Coreflood servers,
    the government replacements received nearly 800,000 command requests, or
    "beacons," from Coreflood-infected machines in the U.S. A week later,
    the number of beacons had plummeted to less than 100,000.

    "Two possible reasons why the Coreflood Botnet is getting smaller are as
    follows: (i) because Coreflood has not been able to update itself on
    infected computers, anti-virus vendors have been able to release virus
    signatures capable of detecting the latest versions of Coreflood,"
    Neumiller said in her affidavit. "And (ii) as victims of Coreflood are
    notified of their infected computers, they may be disconnecting the
    infected computers from the Internet or taking other measures to disable
    or remove Coreflood."

    The restraining order, which was transformed from "temporary" to
    "preliminary" this week by U.S. District Court Judge Vanessa Bryant,
    allows the DOJ and FBI to identify infected computers using IP
    addresses. The agencies then notify the ISPs (Internet service
    providers) responsible for those addresses; the ISPs are to send the
    owners of those PCs a form letter telling them that their computer is
    infected and urging them to run tools to delete the malware.

    While the volume of beacons from U.S. PCs has fallen to one-tenth of the
    number prior to the takedown, Neumiller noted that beacons from foreign
    machines -- which haven't received instructions to stop running the bot
    -- have not dropped as rapidly. As of last Friday, beacons from foreign
    PCs were about a quarter that of April 13.

    Neumiller also said that the FBI has identified "seventeen state or
    local government agencies, including one police department; three
    airports; two defense contractors; five banks or financial institutions;
    approximately thirty colleges or universities; approximately twenty
    hospital or health care companies; and hundreds of businesses" infected
    with Coreflood.

    Microsoft today said it was releasing another edition of its Malicious
    Software Removal Tool (MSRT) to bolster the cleaning process.

    "This edition includes variants of Afcore released by the criminals
    behind it at approximately the same time as the previous edition of
    MSRT." said Jeff Williams, a principal group program manager with the
    Microsoft Malware Protection Center.

    Typically, Microsoft ships a new version of its Malicious Software
    Removal Tool (MSRT) only once each month as part of its Patch Tuesday
    package. The free MSRT, which targets a limited number of malware
    families, scrubs PCs of attack code. Microsoft feeds the tool to users
    through the same Windows Update mechanism that serves up security

    Microsoft said earlier this month that it added Coreflood detection to
    the April 13 version "at the request of the FBI and the Department of
    Justice." Today the company declined to confirm whether it re-released
    the tool at the request of the DOJ and FBI.

    Neumiller's affidavit included a chart that showed a resurgence in
    Coreflood beacons on April 18. That spike may have prompted the DOJ and
    FBI to ask Microsoft to reissue MSRT.

    Microsoft's newest version of the MSRT can be manually downloaded from
    the company's Web site. Windows PCs should receive the revised tool
    shortly via the Windows Update service.
    Virus Guy, May 6, 2011
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  2. The coreflood botnet takedown was announced in a.p.s on 4/15


    RLK-F added the following...

    David H. Lipman, May 6, 2011
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  3. Thanks, David and Rhonda.

    The PDF is thought to be damaged by my reader, I'll try again.
    FromTheRafters, May 6, 2011
  4. Virus Guy

    Virus Guy Guest

    "David H. Lipman" unnecessarily full-quoted:
    What group is a.p.s?

    Still doesn't explain if this is essentially the same malware that's
    been in circulation (and in use?) for the past 8 years (coinciding with
    the introduction of win-XP I suppose...)
    Virus Guy, May 6, 2011
  5. Sorry, I used News Group shorthand.

    David H. Lipman, May 6, 2011
  6. Virus Guy

    Virus Guy Guest

    Shorthand is fine (normally).
    Is that a more appropriate, relevant, topical, or useful place to find
    discussions about trojans and botnets?

    Does coreflood fall into the catagory of spyware?
    Virus Guy, May 7, 2011
  7. Not really but due to overlap it wasn't OT.
    David H. Lipman, May 7, 2011
  8. It didn't work even after I downloaded it to my desktop.

    I booted up an old BT3 Linux Live CD and it opened up just fine there.
    Maybe I need to replace my pdf reader on Windows. Thanks for the link.

    Once the government gets a taste of the botherding business, I wonder if
    they'll be able to quit. :eek:)
    FromTheRafters, May 7, 2011
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