Redirect virus

Why does avast not catch redirect viruses. Avast does not catch the virus at the time of infection or with a scan. This does not make me want to purchase a full version if i have to purchase a separate program to remove this type of virus. Does anyone have any solid advice on completely removing these.

no security program have 100% detection…
redirect virus are usually not a virus but a browser hijacker, and they usually comes bundled with something you downloaded and installed… have you got a new toolbar in your browser?

these may be detected as PUP = not a virus / Possible Unwanted Program
PUP scan is default off in quick/full scan

follow guide and attach logs. (not copy and paste) http://forum.avast.com/index.php?topic=53253.0

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