Re: Isn't spam a ISP issue?

On Mar 18, 2013, at 8:45 AM, Chris Lewis <[email protected]> wrote:

> On 13-03-18 04:03 AM, Kurt M wrote:
> 
>>> You are assuming that legitimate bulk mail is the biggest issue here
>>> and not the various examples of; user accounts with stolen credentials
>>> (ex: Ongoing Y! issues), the recent uptick in spam from compromised
>>> web hosts, bots, malware, ISPs that don't/wont enforce AUPs, ISPs that
>>> don't know any better (emerging markets).
>> 
>> Not at all, they are maybe 1-2%, but as I said, what I still can see, using an
>> ISP mailer seems still to be the most common way to spam, not setting up your
>> own MTA.
> 
> Er no.  At present approximately 50% of all spam comes from compromised
> *ix web servers using direct-to-MX PHP and perl SMTP spamming tools.
> 
> Most of the rest is direct-to-MX Windows trojans (festi, kelihos,
> cutwail et. al.).
> 
> Using an ISP MTA for spam hasn't been common for the a decade or so.

And yet, I still get a lot of spam from ISP smarthosts, and it's often the
trickiest to filter (or otherwise deal with, as the ISPs involved don't care
and wholesale blocking of their outbounds is problematic).

Just because it's not a big fraction of the volume doesn't mean it's not
a sizable fraction of the problem.

Cheers,
  Steve