Recommended security add-ons

[mixture]

Do you have evidence that the bot nets are set up in that way?

Researchers from UC-Santa Barbara took over the Torpig Botnet for 10 days.

Their report contained a couple of interesting paragraphs on DHCP and NAT :

The DHCP effect:

As we discussed, during our ten days of monitoring, we observed 182,800 bots. In contrast, during the same time, 1,247,642 unique IP addresses contacted our server.

The NAT effect:

By looking at the IP addresses in the Torpig headers we are able to determine that 144,236 (78.9%) of the infected machines were behind a NAT, VPN, proxy, or firewall. We identified these hosts by using the non-publicly routable IP addresses listed in RFC 1918: 10/8, 192.168/16, and 172.16-172.31/16. We observed 9,336 distinct bots for 2,753 IP addresses from these infected machines on private networks. Therefore, if the IP address count was used to determine the number of hosts it would underestimate the infection count by a factor of more than 3 times.

[IO540]

All that could simply mean that there are millions of people out there who click on every p0rn site link they can find

After all, according to a Cisco mate of mine, p0rn accounts for the majority of internet traffic

Same with emails.

[Mike-Bracknell]

Originally Posted by IO540

Malwarebytes also failed to see anything. In fact it has found nothing at all when I have run it - except in one case of a laptop on which it found 13 trojans

This is why you need to run Malwarebytes via safe mode with command prompt. Because in the vast majority of recent viruses the main method of defence employed by the virus has been to 'hide' itself from whatever AV you're using at the time....and this is hooked into explorer.exe. The ONLY version of booting Windows which doesn't invoke explorer.exe is safe mode with command prompt (and then manually navigating to, and executing mbam.exe). I've had machines which say "0 files infected" when booted normally, which then say "100 files infected" in safe mode with command prompt.

Were they infected while sitting there switched on, with nobody using them?

Not recently, but then recently things have got better with patching, firewalls, AV readily available. In the past, yes.

How does one access a PC behind a NAT router, which has no open ports?

Initially, you spoof the source address or run a man-in-the-middle attack.

And if you get through the router, the PC (assuming it is running windoze with the main patches applied) will still present the attacker with a login prompt, or the attacker will need login credentials if you are going in via a LAN. That's if the PC has been configured to ask for a login+password. If not, one important element of security has been lost.

You assume that all inter-process communication is password protected. And/or that hackers intend to use things like CIFS shares for access?

Let me give you one relevant example. The recent Anonymous attacks have been related to SQL injection hacks, where SQL servers have been exploited by sending malformed requests, leading to them coughing up things like passwords or other otherwise hidden documents. Now, consider a SQL server running on a PC (not an unknown phenomenon on a lot of PCs that otherwise don't need it), sat waiting for querying. It doesn't take too much of a leap of faith to see that if there was access to that server you could be susceptible to a security breach of the PC. Now what if you had access through NAT to the port? pretty easy to hack, huh? Especially if you remember that NAT holds the port open for a fair amount longer than it takes to transmit the data. Not too difficult to gain access in that regard, if the port's opened for some reason or another.

[Mike-Bracknell]

Originally Posted by IO540

After all, according to a Cisco mate of mine, p0rn accounts for the majority of internet traffic

Your Cisco mate needs to update his/her knowledge:

Porn passed over as Web users become social: author | Reuters

[daved123]

The time has come - update2

Indeed A.O, as the original poster on that thread and recipient of the advice from Mr Mike of Bracknell-world - I gave an update on the installation process and 4months later, can further report that everything has since run smoothly and efficiently and I can honestly recommend it.
DaveD

[Ancient Observer]

Me, I just do what I'm told so I have a Mike from B set up on my new pc.

[mixture]

Ancient Observer,

Me, I just do what I'm told so I have a Mike from B set up on my new pc.

Yeah, he's one of those rare few good things to have emerged from Bracknell in the past millenium.