Received two of the same scam calls regarding highjack of my VirginMedia broadband.
Both call appear to come from a call centre but show on my call log as different local exchange numbers. How are they cloning local numbers and are VM aware of this?
Yes, VM are well aware as there are many topics on here about this subject.
Legitimate companies may want to show a particular phone number on caller ID when placing outbound calls (such as a general switchboard number or a local office number for international companies). Scammers have simply taken advantage of this feature.
In the past the scammers have tended to use random or non-existent numbers. From the topics on here, it seems as if they are increasingly using real telephone numbers (cloned from innocent legitimate businesses or residential users) and are matching the 'stolen' numbers to the numbers of the exchange being called by the scammers. They do this to try to add an air of authenticity to the call. OFCOM publish lists of number blocks for particular area codes and which companies own the numbers (which the scammers also exploit).
As it is so easy to misrepresent a call ID number, you can place no trust whatsoever in using a caller ID number to identify the caller.