[Full-disclosure] Ports used by trogens

[Brian Phillips <brianphillips@xxxxxxxxxx>]

I read some time ago that malicious code when reporting home did not use 
port 80 or any of the other well known ports used for simple internet 
work. This means, as I understand it, that the home computer of the 
malicious code is constantly listening on some port other than port 80.

Is it still the case that the standard ports are not used by malicious 
code when reporting home?

If malicious code does not used the standard ports, then why not?   As 
far as I can see (and my knowledge is very basic) there seems to be no 
reason why outgoing traffic from, say, a home computer, should not be 
directed to port 80 on the IP address of the home computer of the 
malicious code.

This question is of interest because one frequently see advice to the 
effect that all outgoing ports other than those which are required for 
use should be blocked.   Clearly, if malicious code now uses, say port 
80, then blocking unused ports will not increase the security of a 
computer.

Any comments (or corrections) would be gratefully received.

Regards

Brian
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