The SpamTool.Win32.Small.b we detected on February 15 harvests emails on infected machines selectively: it excludes addresses with subtext strings containing parts of av vendor names. It turns out that it had been preparing todays Bagle outbreak. The latest variants follow hard on the heels of our updates and we suspect that the authour is creating new variants every time we release updates to block previous versions. Today we have already intercepted 15 new pieces of malware produced by the authorour of Bagle.”]
Source: https://securelist.com/bagle-and-spamtool-hand-in-hand/29971/