Between November 2017 and April 2018, someone used German parcel delivery service DHL to sent out several so-called improvised explosive devices (IEDs) in packets, demanding €10 million worth of bitcoins from the parcel service.
In one event, a parcel containing nails, screws, and fireworks explosive powder was received by a pharmacy adjacent to the German Christmas market during 2017 Christmas, which eventually caused the evacuation of the market.
German police later discovered a message inside that package in which the blackmailer threatened to send more parcels in the pre-Christmas season unless DHL made a 10 million euro payment in Bitcoin.
During the investigation, the German police successfully communicated with the alleged blackmailer multiple times via an email and succeeded in capturing his/her Motorola brand device's MAC address f8:e0:79:af:57:eb, which was allegedly connected to several public Wi-Fi networks in Berlin at different times.
Since every electronic device comes with a unique MAC address, German police are trying to use this information to map out all Wi-Fi networks that the culprit used, probably in hope to pinpoint the right CCTV footages and trace the offender.
Though MAC address of a device can be spoofed easily, State Criminal Police Office LKA Brandenburg has requested citizens to check their wireless routers and network logs for the given MAC address and provide relevant information to the agency via email to email@example.com.
"Private households can also unknowingly or knowingly operate open networks. The alleged perpetrator could also have used this for his communication," the Police say.
To search for this MAC address, open your router's configuration panel in the web browser (usually at https://192.168.1.1) and then, depending upon the router, open the log file section and search for f8:e0:79:af:57:eb on the page.