Hacked PAYG SIM?

[Anonymous]

My 85-year-old dad has an O2 PAYG phone which he tops up every month. Recently, he noticed that his credit has been falling quicker than usual.

When I called to get him to check if he'd been ringing 08/09 numbers, he said he'd just gone out and bought a new phone. I thought nothing more about it. I turns out that he'd been sold a new phone, and transferred the SIM. The credit continued to fall faster than expected.

My dad went into the O2 Shop and asked about this. He told me that the people in the shop told him that he had probably given out his mobile number to someone dodgy over the internet, and they had used the credit on his SIM. They gave him a new SIM, and suggested he only gave his mobile number to reputable companies.

Now, this all sounds a bit strange to me. Surely people give out their mobile numbers all the time. How can this be exploited? Does anyone know what has likely happened here, and possibly the O2 staff meant?

[jonsie]

I would suspect that the phone is connecting to the internet to update anything running in the background. Make sure mobile data is switched off.

The only other explanation is that your father is receiving premium text messages from a short code number in which case he needs to text STOP ALL in reply.

[perksie]

I agree with jonsie a new phone is probably using data as most can now connect to the internet automatically unless you turn data off.

[Anonymous]

You guys beat me to it. My old nan (rip) used to sometimes use over a tenner a day when she had accidently connected to the internet and left it on all day. 

[Anonymous]

Unlikely to be data, I think, as his old phone was virtually a brick and didn't even do email.

I don't know what he has now, but the problem started before the new phone anyway. I'm guessing it's a slightly more modern brick. 😉

He never mentioned getting any texts, but that doesn't mean he wasn't. I'll ask him about that.

The Premium Text sounds like the only way a number can be hammered. I've not had one of these myself. Don't you have to ask for them by text in the first place? Otherwise anyone could be charged without permisison.

[jonsie]

Sometimes just inadvertently clicking on a link on a website gives them 'permission' to start a subscription.

[Anonymous · Accepted solution]

It can be done really inncocently, that would be my first point of call. 
My old nan used to leave the voicemail on as well. 

The other guys may be able to help but I am sure I remember that there used to be a issue with how mobile phone numbers were set up on phones For ex: +44 7958------ causing extra charges.

[Anonymous]

It was a sudden recent development, and the number began 7761, so I don't think it sounds like that.

I did wonder about voicemail. Very topical at the moment!

[Anonymous]

Well keep us informed of your findings, sure if we think of anything else we will all post again.

[Liquid]

I wonder if its possible to send a blank txt if its blank the phone wouldn't have anything to display. Could be a new scam:/