Pierluigi Paganini July 07, 2012

The story begins in November 2011 when in Estonia was arrested a group of persons accused of having developed the dreaded trojan that seems to be able to spread with surprising ease building a scary botnet.

The botnet operated by Rove Digital altered user DNS settings, pointing victims to malicious DNS in data centers in Estonia, New York, and Chicago. The malicious DNS servers would give fake, malicious answers, altering user searches, and promoting fake and dangerous products. Once discovered the cybercrime the FBI to give businesses and private individuals affected by DNSChanger time to clean infected systems has replaced the Trojan’s DNS infrastructure with surrogate, legitimate DNS servers. Replacing the command server the feds have prevented the worm propagation. The FBI took over the botnet’s command-and-control (C&C) servers in November as part of Operation Ghost Click.

In a first time, under a court order, expiring March 8, the Internet Systems Corporation planned the replacement DNS servers for the Rove Digital network. This will allow affected networks time to identify infected hosts and avoid sudden disruption of services to victim machines.

Despite the calls provided by the press and the major law enforcement, the situation is far from reassuring, because too many PCs are being infected and potentially damaged by the planned blackout. More than 3 million PCs worldwide were still infected with DNSChanger in March 2012, so authorities extended the period before the planned shutdown of the surrogate servers.

In March a federal judge has postponed, with an order, the blackout of the surrogate servers of 120 days (until July 9, 2012) to give companies, businesses and governments more time to arrange the response to the threat.

July 9th has arrived!

What will happen on Monday?

The situation is precarious, it has been estimated that tens of thousands of U.S. internet users could be left still infected by DNSChanger malware. The estimations are of 64,000 users in the United States, plus additional 200,000 users outside the United States with a total profit several millions of dollars.

Every machine is still infected on July 9th will not able to navigate correctly querying the DNSs, contrary to popular belief, despite numerous appeals from law enforcement, according to Internet Identity about 58 of the Fortune 500 companies and two government agencies have at least one computer or router that is still infected.

Fortunately, today is very easy to sanitize the infected machine, every security firm has provided its tool do it, more information on how to detect and clean up the malware can be found on a website www.dcwg.org. The FBI has also created a web page to check if our computer is using a rogue DNS, simply providing its IP-address.

Following a short list of removal tools

• Hitman Pro (32bit and 64bit versions)
• Kaspersky Labs TDSSKiller
• McAfee Stinger
• Microsoft Windows Defender Offline
• Microsoft Safety Scanner
• Norton Power Eraser
• Trend Micro Housecall
• MacScan
• Avira

Managing a network of servers in my judgment, however, presents additional risks. History has taught us that no infrastructure is safe, the Pentagon’s networks are for admission of the government, been hacked several times, on several occasionsAnonymous groups have made fun of defense systems of private companies and government agencies.
Well, the decision to postpone the shutdown of the servers could open the door to a much more serious scenario.

I completely disagree with the decision to keep alive a network of surrogate servers to date, the choice presents too many risks. Imagine what would happen if the control of the network of rogue servers ended up in the wrong hands, allowing, for example, a massive diffusion of more malicious and dangerous malware.

Pierluigi Paganini

(Security Affairs – DNSchanger, malware)

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