Hey, I think that the detect ion by your Microsoft security essential was Alureon since this rootkit is the only malware. But I am also aware about this that why Microsoft security essential should disinfect rather than quarantine or remove. I think that this thing might be happens because of Alureon contained file was data file or it will be the word document file for that reason only Microsoft security essential don’t remove it , it only disinfect that file. According to me Alureon is a Trojan and bootkit which is designed, amongst other things, to steal data by intercepting a system's network traffic.
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