Infected PCs- The French law enforcement agency, National Gendarmerie, today announced the successful takedown of one of the largest wide-spread RETADUP botnet malware and how it remotely disinfected more than 850,000 computers worldwide with the help of researchers.
Earlier this year, security researchers at Avast antivirus firm, who were actively monitoring the activities of RETADUP botnet, discovered a design flaw in the malware’s C&C protocol that could have been exploited to remove the malware from victims’ computer without executing any extra code.
However, to do that, the plan required researchers to have control over the malware’s C&C server, which was hosted with a hosting provider located in the Ile-de-France region in north-central France.
Therefore, the researchers contacted the Cybercrime Fighting Center (C3N) of the French National Gendarmerie at the end of March this year, shared their findings, and proposed a secret plan to put an end to the RETADUP virus and protect victims.
According to the proposed plan, the French authorities took control over the RETADUP C&C server in July and replaced it with a prepared disinfection server that abused the design flaw in its protocol and commanded the connected instances of the RETADUP malware on infected computers to self-destruct.
“In the very first second of its activity, several thousand bots connected to it in order to fetch commands from the server. The disinfection server responded to them and disinfected them, abusing the C&C protocol design flaw,” the researchers explain in a blog post published today.
“At the time of publishing this article, the collaboration has neutralized over 850,000 unique infections of RETADUP.”
According to Jean-Dominique Nollet, head of the National Criminal Intelligence Service at Gendarmerie Nationale, the authorities will keep the disinfection server online for a few more months as some infected computers have not yet made a connection with the police controlled C&C server—some have been offline since July while others have network problems.