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Re: [LUG] In the Press

 

On 19 Dec 2013, at 20:33, Martijn Grooten <dcglug@xxxxxxxxxxxxxxxxxx> wrote:

> On Thu, 19 Dec 2013, Simon Waters wrote:
>>> But I don't remember ever seeing (or hearing about) a botnet performing an 
>>> actual dictionary attack on a domain. It's just not worth it.
>> 
>> Think we must be misunderstanding each other. Dictionary harvesting attacks are 
>> usually done using long lists of names, it is a well established technique, even 
>> has its own Wikipedia article.
> 
> You're right of course. I meant: on the kind of domains that people who give 
> unique email addresses to every organisation they deal with.
> 
> I can imagine it occasionally happening on larger domains with a lot of users, but 
> even there I would think it doesn't make much sense from a spammer's point of view.

Well a typical ADSL connected PC could guess several hundred email addresses a 
second across many domains, we saw botnets of 10,000, so that ~4,000,000 guesses a 
second.

Assuming they pre-select their domains for a 1% hit rate of addresses existing 
(generous) that is 40,000 email addresses a second.

If 10% open it, that is 4,000 validated email address, at 2 cents an address and you 
sell the list multiple times, it is generating multiples of $80 worth of email 
addresses to sell per second.

Okay 1% is optimistic, but the thing is the marginal cost on most of this is near 
zero, once you have your botnet you do whatever makes the most money, bitcoin mining 
may save us all from a worse fate, although presumably you could spam and bitcoin 
mine at the same time since one saturates CPU, the other bandwidth.
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