Seeing an email from your firm’s managing partner flash up on your phone is something that would give even the most laid-back lawyer pause for thought, let alone if your boss is asking to see you urgently.

But before typing back a quick, slightly panicked response, asking what’s wrong and why they are needed, lawyers are now having to confront a different, more sinister possibility: is this email really coming from my boss? Or is it coming from a total stranger?