Blaming avast! for it just makes you look like an idiot so I suggest people not to do that. The hack of Piriform was on the way before AVAST purchased it. Especially since Piriform was never a security focused company, it was just a small software studio that started with a "tweak/cleaner" utility and grew over time.
However, this incident raised an important issue of trusting digital signatures entirely. Most AV solutions entirely skip ALL security checks if valid digital signature is found. Which was also the case in CCleaner's case. For example, Comodo trusts signed files entirely, making such files bypass their "containment sandbox" feature entirely. This just shows how their "perfect" containment system is really "perfect". And same goes for the rest, avast! included. avast! also checks digital signatures to avoid false positives and if valid, it'll not perform further file checks. And I think that's a mistake. Signatures should provide a guidance and not an absolute declaration of clean or malicious.
