Faheem: Explaining URLs to people using a Slack bot

Online safety regularly depends on users' ability to know either where a URL is likely to lead or identify when they are on a site other than they expect. Unfortunately, the combination of low URL reading ability in the general population and the use of hard-to-detect approaches like look-alike letters, makes the reading of URLs quite challenging for people. We design a Slack chat bot, named Faheem, which assists users in identifying potentially fraudulent URLs while also teaching them about URL reading and common malicious tactics. In this work we describe the design of the chat bot and provide an initial evaluation. We find that Faheem does a good job of interactively helping users identify issues with URLs, but Faheem users show minimal retention of knowledge when they loose access to the tool.