Tracking down HTTP push notifications | Opendium

We were recently contacted by one of our customers to investigate some popups that were appearing on one of their users' workstations. The user, who was thankfully a member of staff, received a popup notification asking "Do you like big girls?" and featuring some fairly risqué pictures.  The customer was obviously concerned that this had not been picked up by their filtering and so asked us to investigate why this had happened.