In a Twitter discussion last week on ransomware attacks, KrebsOnSecurity noted that virtually all ransomware strains have a built-in failsafe designed to cover the backsides of the malware purveyors: They simply will not install on a Microsoft Windows computer that already has one of many types of virtual keyboards installed — such as Russian or Ukrainian. So many readers had questions in response to the tweet that I thought it was worth a blog post exploring this one weird cyber defense trick.