According to SC Magazine, Kraken, a large and difficult-to-detect botnet that peaked in 2008 and was dismantled by early 2009, is back, and anti-virus solutions are struggling to detect it.

The botnet reappeared in April and, as of last week, was made up of more than 318,000 unique IP addresses, or about half its 650,000 maximum size in 2008, Paul Royal, research scientist at the Georgia Tech center told SCMagazineUS.com on Wednesday.

Read the full article posted by SC Magazine: Kraken botnet re-emerges 318,000 nodes strong