New Massive Botnet Twice the Size of Storm - Dark Reading

Weighs in at 400,000 bots. Nice knowing you, Storm...

The so-called Kraken botnet has been spotted in at least 50 Fortune 500 companies and is undetectable in over 80 percent of machines running antivirus software. Kraken appears to be evading detection by a combination of clever obfuscation techniques, including regularly updating its binary code and structuring the code in such a way that hinders any static analysis, says Paul Royal, principal researcher at Damballa.

"It's easy to trace but slow to get antivirus coverage. It seems to imply [the creators] have a good understanding of how AV tools operate and how to evade them," Royal says.
[via Slashdot]