I am not sure this is the right community, but my problem originated with me travelling abroad.
I've travelled to Germany about a month ago (and I am still staying there). About two weeks later I''ve been informed by two people from my home country that they have missed calls from some unknown cell numbers in Germany (numbers are starting from +49). I've never disclosed their numbers to anyone, but those are the people I call quite frequently (my gf and my father).
What could be the cause? I think they are getting scammed, but how could attacker get hold of their cell numbers?
EDIT: some more information:
- I've been to France in July and nothing similar happened
- Those missed calls do not coincide in time with me calling my contacts
- I am using an Android phone and I have scanned it with an antivirus - it did not find anything
- the only German application I have installed during my stay abroad was an official public transportation app
- I don't see any suspicious calls in my call history
- I am using my home network SIM card for roaming
As far as I can tell those are mobile numbers
This may be important: I have tried searching for the numbers and did not find any reports about those exact numbers. BUT all of them start with the same digits: +49176, followed by eight other digits, different in case of each call. I have found one source that says this is a prefix used by German o2 network (which, curiously, is the network I use here for roaming). I have found a number of reports from people who received unwanted calls from numbers in this format - some people identify source as German, other say that the number only looks like German but originates from elsewhere. Nevertheless, I find it a strange coincidence that the people I know have started receiving those calls - from numbers which start with German country code - after I arrived in Germany.