Well, my link in Reply #21 shows that Avast has alerted on ClamWin since at least 2009.

There have been some changes at ClamAV since Sourcefire acquired them and Immunet about a year ago. One notable improvement has been the implementation of automated signature creation five or six months ago, which has greatly increased the detection rate of ClamAV, hence ClamWin and Immunet. If I had to guess, I would say the change in signatures is more likely causing your sudden detection of ClamWin, rather than a recent program update, which have mostly been minor bug fixes.

Regards, Simion