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Food writer Jack Monroe loses at least £5,000 in SIM-swap fraud

Her accounts were drained in spite of using 2FA, showing that SIM swaps can still circumvent what's a good security tool.

British food writer and activist Jack Monroe has had her bank account drained by hijackers, despite using two-factor authentication (2FA) to protect accounts.

On Friday, Monroe tweeted that her phone number had been SIM-jacked: hit with SIM swap fraud that enabled a hijacker to take over her phone number, intercept the codes sent for the 2FA she says she uses on all her accounts, and drained her accounts of what appeared, at least initially, to be about £5,000 ($6,350) – a figure that could rise.

The self-employed freelancer, who says she has to hustle “for every pound I earn,” said that her card details and PayPal information were apparently intercepted during an online transaction. Meanwhile, her phone number was ported to a new SIM card, Monroe said.

SIM swap fraud is one of the simplest, and therefore the most popular, ways for crooks to skirt the protection of 2FA, according to a warning that the FBI sent to US companies last month.

How the crooks swing a SIM swap

As we’ve explained, SIM swaps work because phone numbers are actually tied to the phone’s SIM card – in fact, SIM is short for subscriber identity module, a special system-on-a-chip card that securely stores the cryptographic secret that identifies your phone number to the network.

Most mobile phone shops out there can issue and activate replacement SIM cards quickly, causing your old SIM to go dead and the new SIM card to take over your phone number…and your telephonic identity.

That comes in handy when you get a new phone or lose your phone: your phone carrier will be happy to sell you a new phone, with a new SIM, that has your old number.

But if a SIM-swap scammer can get enough information about you, they can just pretend they’re you and then social-engineer that swap of your phone number to a new SIM card that’s under their control.

By stealing your phone number, the crooks start receiving your text messages along with your phone calls, and if you’ve set up SMS-based 2FA, the crooks now have access to your 2FA codes – at least, until you notice that your phone has gone dead, and manage to convince your account providers that somebody else has hijacked your account…

…which, hopefully, Monroe can do.

On Tuesday, she said that so far, she’s “played nicely” because she wants her phone number and money back, but that as soon as she gets them, she’s “going to town on both my phone provider and bank for allowing this to happen.”

Valuable PII posted publicly

Monroe said that at least one type of identity verification information – her birthdate – is publicly available, in her Wikipedia entry, so there’s no obfuscating that. (Though those of us who aren’t public celebrities with Wikipedia pages should at least try to keep that personally identifiable information [PII] out of the public eye.)

She pre-empted potential cybersecurity finger-wagging by pointing out that she doesn’t use publicly available email addresses on her financial accounts and that her passwords are “gobbledegook letters and numbers and special characters” – in other words, she’s using proper, tougher-than-nails, and, one assumes, unique passwords.

(If you need to know how to cook up such passwords, please do read this. If you reuse the same password(s), please don’t. Here’s why it’s a bad idea.)

What to do?

When it comes to avoiding SIM swap fraud, Paul Ducklin has useful tips, and they’re certainly worth repeating now:

Watch out for phishing emails or fake websites that crooks use to acquire your usernames and passwords in the first place. Generally speaking, SIM swap crooks need access to your text messages as a last step, meaning that they’ve already figured out your account number, username, password and so on.

Avoid obvious answers to account security questions. Consider using a password manager to generate absurd and unguessable answers to the sort of questions that crooks might otherwise work out from your social media accounts. The crooks might guess that your first car was a Toyota, but they’re much less likely to figure out that it was a 87X4TNETENNBA.

Use an on-access (real time) anti-virus and keep it up-to-date. One common way for crooks to figure out usernames and passwords is by means of keylogger malware, which lies low until you visit specific web pages such as your bank’s logon page, then springs into action to record what you type while you’re logging on. A good real time anti-virus will help you to block dangerous web links, infected email attachments and malicious downloads.

Be suspicious if your phone drops back to “emergency calls only” unexpectedly. Check with friends or colleagues on the same network to see if they are having problems. If you need to, borrow a friend’s phone to contact your mobile provider to ask for help. Be prepared to attend a shop or service centre in person if you can, and take ID and other evidence with you to back yourself up.

Consider switching from SMS-based 2FA codes to codes generated by an authenticator app. This means the crooks have to steal your phone and figure out your lock code in order to access the app that generates your unique sequence of logon codes.

Having said that, switching from SMS to app-based authentication isn’t a panacea.

Malware on your phone may be able to coerce the authenticator app into generating the next token without you realizing it – and canny scammers may even phone you up and try to trick you into reading out your next logon code, often pretending they’re doing some sort of “fraud check”.

If in doubt, don’t give it out!


She should have noticed that her mobile phone was disconnected from the cellular network. When the scammers did the SIM swap it would have immediately de-activated her current SIM card and she would have seen “no service” message on her mobile phone.


We do indeded advise people to keep their eye open for unexpected loss of mobile phone service – if you have friends or colleagues nearby who use the same provider but who *do* have service, that’s a strong warning signal (no pun intended). But saying someone ‘should have noticed’ is a bit harsh – sure, you *might* notice…

…but you might not. For example, what if you’re not looking at your phone at the moment it goes offline? Assuming you sleep for five to eight hours in chunk every day, that gives the crooks a lengthy and regular window during which you almost certainly *wouldn’t* notice a SIM swap.

Also, there is the thorny problem if your phone goes dead and you suspect a SIM swap, it doesn’t help much to notice immediately given that you can’t contact your mobile provider to tell them, because your phone is dead!


I’m with Duck on this one. That’s like blaming the victim. I sometimes don’t even turn my phone on for a day or two because … well… I don’t need it.
I have just today contacted my service provider and arranged for a secondary security measure if I ever need to port my number. It was dismaying when I spoke to their rep and found that they were unaware of Sim-swap fraud. Or maybe they just claimed to be unaware so as not to alarm me.


I mean technichally it would be a fraud check. They are fraudulently “checking” your next code to see if it works


Her name is Jack?



The UK has very few regulations about names – IIRC you can largely go by what you like, provide you don’t take a new name for deceitful or fraudulent reasons, and you can change your name unilaterally (AFAIK, you prepare, sign and have witnessed a document called a Deed Poll, which is a sort of one-person contract in which you affirm that you [a] now go by a new name and [b] no longer go by your old name).

Apparently, the only unbendable rule is that you can’t go by a mononym, at least officially, so you can’t change your name to get a passport or a driving licence issued as, say, “Pele” or “Cher”. You have to have at least two names. That rule applies when registering a birth, too. (I know someone who tried to call his daughter by a single name, but the Register Office gave him short shrift and made him come up with a surname as well.)


“But if a SIM-swap scammer can get enough information about you, they can just pretend they’re you and then social-engineer that swap of your phone number to a new SIM card that’s under their control.”

is missing the large number of times where crooks don’t actually know that much about their target but just bribe someone at the mobile carrier to perform the SIM swap. When this is happening it doesn’t really matter how much you protect your PII as they are just using your name (and maybe your phone number but they don’t even have to know that). Attempting to hide your PII is good, but really not very useful advice for people being targeted by SIM swaps.

If you are a celeb, politician, crypto-bro, etc then a software authenticator or hardware token is really your only option. SMS just doesn’t cut it.


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