Pattern recognition for computer security : discriminative models for email spam campaign and malware detection Computer Security deals with the detection and mitigation of threats to computer networks data and computing hardware. Thisthesis addresses the following two computer security problems: email spam campaign and malware detection.Email spam campaigns can easily be generated using popular dissemination tools by specifying simple grammars that serve as message templates. A grammar is disseminated to nodes of a bot net the nodes create messages by instantiating the grammar at random. Email spam campaigns can encompass huge data volumes and therefore pose a threat to the stability of the infrastructure of email service providers that have to store them. Malware software that serves a malicious purpose is affecting web servers client computers via active content and client computers through executable files. Without the help of malware detection systems it would be easy for malware creators to collect sensitive information or to infiltrate computers. The detection of threats such as email spam messages phishing messages o…