Schrader said the best defense against Trojan Horse e-mail viruses is end-user education -- and, of course, updated virus-scanning software.

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There are countless repositories of fantastic educational content, from user-generated and curated sites to Open Education Resources to private sector publisher sites.

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In addition to the simple education of users, Adams advises businesses to develop clear policies governing user-owned devices to avoid difficult confrontations with staff if a device is lost, stolen or compromised.

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