Hello all. First of all, sorry about my english. I only want to say that we have several customers that reported us the same problem: numerous messages with the message of "time out" related with winlogon.exe.
In all the cases we solved the problem with hijackthis, but I am sure that there is some malware circulating that is not detected by avast! not by the majority of antispyware programs (these customers tested many programs of this type), which were not finding anything in the troubled computers. And since it has been said hereabouts, it is a question of a program that uses the pc of the victim as a zombie to send spam.