A file may drop a backdoor.Logical formLearned from2 sentences. A backdoor may be connected to a host.Logical formLearned from2 sentences. A backdoor may be runed.Logical formLearned from2 sentences. A part of a backdoor may be installed on a computer.Logical formLearned from2 sentences. Backdoors may be controlled.Logical formLearned from2 sentences. A backdoor may provide access to a computer.Logical formLearned from2 sentences. A number may pertain-to a backdoor.Logical formLearned from2 sentences. Backdoors can be simple.Logical formLearned from2 sentences. Backdoors may send a notification to e-mail.Logical formLearned from2 sentences. Some backdoors may show (error messages).Logical formLearned from2 sentences. Some worms may drop backdoors to systems.Logical formLearned from2 sentences. Backdoors can be to systems.Logical formLearned from2 sentences. Parts can be constituted-of-or-filled-with backdoors.Logical formLearned from2 sentences. Hackers may use backdoors.Logical formLearned from2 sentences. A backdoor may consist of some parts.Logical formLearned from2 sentences.