New Windows Worm Builds Massive Botnet

The worm exploiting a critical Windows bug that Microsoft Corp. patched with an emergency fix in late October is being used to build a new botnet, a security researcher said today.

Ivan Macalintal, a senior research engineer with Trend Micro Inc., said that the worm, which his company has dubbed "Downad.a" -- it's called "Conficker.a" by Microsoft and "Downadup" by Symantec Corp. -- is a key component in a new botnet that criminals are creating.

"We think 500,000 is a ball park figure," said Macalintal when asked the size of the new botnet. "That's not as large as some, such as [the] Kraken [botnet], or Storm earlier, but it's still starting to grow."

Computerworld Article