The Rustock botnet is now less than half the size it was in March, thanks to the Microsoft led takedown in that month.
The giant spamming botnet was dealt a serious blow when Operation b107 severed the connection between Rustock's command and control structure and hundreds of thousands of computers operating under its control.
The number of systems powering the Rustock botnet was reduced from 1,601,619 to 702,860 between March and June, according to known IP address infections recorded by Microsoft.
This represented a 56.12 per cent reduction. In India, where Rustock infections were most prominent, the reduction was as high as 69.3 per cent.
"That's great news and the infection reduction has happened much more quickly than it did for Waledac over a similar period of time last year, but we still have a long way to go," said Richard Boscovich, senior attorney for the Microsoft Digital Crimes Unit, in a blog post.
Boscovich called for greater collaboration within the cyber security industry to help take down the bad guys.
"The good news is that we are making progress. The tech industry, policy makers and consumer advocacy groups have helped curb cyber threats through the development of safer products and by increasing public awareness of cyber crime," Boscovich added.
"As we continue our efforts to fight cyber crime, one thing is clear: these threats cannot be tackled alone. It was through the combined effort of Microsoft, the judicial system and the industry that Rustock was successfully taken down."
The International Cyber Security Protection Alliance (ICSPA) was launched yesterday, hoping to facilitate a more collaborative approach, linking up Governments with industry and businesses.
