[jsnell]

The advise is to do literally nothing about it. What effect do you think this specific leak has on you? What kind of adversary do you think will be able to benefit from this data, and how?

The reality is that the data is useless trash, and there is no indication that this has actually leaked from Facebook or is showing any kind of security problem in their systems.

[A4ET8a8uTh0]

<<The reality is that the data is useless trash,

That remains to be seen. People are fairly ingenious when it comes to abusing information and information runs the world now. I will offer an unrelated example, partially because I do not want to give ideas on how to benefit from this. Do you remember when certain entrepreneurial billionaire offered a checkmark for sale, which resulted in people impersonating companies and manipulating their stock price[1]?

Like with most things, any tool is worth what one is able to do with it.

<< The advise is to do literally nothing about it.

I would not advise to panic, but doing nothing is not exactly great advice either. Some re-assessment of one's current security posture may be warranted.

[1]https://www.fiercepharma.com/marketing/eli-lilly-hit-new-twi...

[jsnell]

> Like with most things, any tool is worth what one is able to do with it.

Yes, and given an attacker will not get new capabilities from this data, it is worth nothing.

Any attack that could be feasibly run with a list of nothing but phone numbers associated with some (unknown) WhatsApp account could be done without that list just as easily. That's because of two things: a) phone numbers within a given country are easy to enumerate, b) the WhatsApp account space is dense, i.e. the odds of any legit phone number being used for WhatsApp is high.

> I would not advise to panic, but doing nothing is not exactly great advice either. Some re-assessment of one's current security posture may be warranted.

If you can't formulate a realistic threat from this data, how can you possibly re-evalate your security posture in light of it? You need a threat model for that. Pondering about the security of one's digital life can of course be worthwhile in general, but advising anyone to do so in the context of this linkbait is just advising them to waste their time.

In your Twitter example, the impersonation did not come as a surprise. People were predicting that outcome within minutes of Musk announcing it. Can you make a prediction about what bad things will happen to the people whose phone number is in this dump, compared to people whose phone number isn't there?

[A4ET8a8uTh0]

<< If you can't formulate a realistic threat from this data, how can you possibly re-evalate your security posture in light of it?

You do have a point and it is possible I misunderstood the 'value proposition' from this data set.

From the forum referenced in the article:

"Name / Whatsapp Number - Country Wise "

What I see in that post is name field ( or potentially just a number ) and country field. If I was a person buying it, the main benefit would be "being able to reach a seemingly random ( unless it is separately checked against some other available list/s ) individual in a desired geographic location". As you correctly assessed, by itself it is not a terrible security threat.

<< Can you make a prediction about what bad things will happen to the people whose phone number is in this dump, compared to people whose phone number isn't there?

Yes ( although admittedly, mostly because "bad things" is sufficiently generic to allow for it and I already admitted I think you are right on the security aspect ).

Fraud-wise this is a perfectly sufficient set of information ( current valid numbers likely corresponding with real phone numbers ) as those tend to be number games anyway ( one out of how many answers a spam email type of deal ). In that area, the most common scam lately is grandson scam[1] or romance scam[2]( those having extra benefit of less likely being reported even if others point it out to the victim ). Seniors do seem to use Whatsapp in the old country partially due to price and reliability ( dunno how common it is in US though ) so they fit that target demographic, but that assumes fraudster can reliably identify a victim set of seniors ( or burn existing set with a more generic pitch ). For non-seniors, crypto scams seemed very common lately ( and how many people just click yes, when an invitation pops up ) although recent crash likely made it less desirable.

In other words, I think you are right about not doing anything specific security-wise, but it may be worthwhile talking with your social circle if they use Whatsapp since they may now see an increase in unsolicited calls/messages/invites and benefit from a conversation about about safety online in general.

[1]https://www.aarp.org/money/scams-fraud/info-2019/grandparent... [2]https://www.fbi.gov/how-we-can-help-you/safety-resources/sca...