From: Darren Reed <avalon @
>Hmmm, I still haven't seen a good anology to port scanning.
^^^^^^^ (nOh gud Anglishe sp. down under :-)
I've always thought a good analogy for port scanning was someone who
dials telephone numbers to see if anyone answers and -- if anyone does
answer -- immediately hangs up.
Its annoying. It can be grounds for a harassment complaint if someone
does it to you frequently but you usually give them the benefit of the
doubt if it happens once or twice (it must have been a wrong number, etc).
And it is impossible to infer anything from the state of mind of the
caller who hangs up (or keeps calling and hanging up). Is it a teenage
prank, a burglar checking to see if anyone is in the house before
breaking in, or a homicidal maniac serial killer ala "Millenium"?
Today it is easier than ever for people being harrassed by 'hang-up'
callers to deal with the problem (previously they had to get a 'trap
and trace' order for their phone to set up a 'pen register' or have the
telco snag the caller using ANI, now they can just go out and buy a
Caller-ID box -- though there ARE ways a caller can circumvent having
their identity revealed via Caller-ID).
Just as with a port scan, once a caller has determined that a port is
active (e.g. someone is home and answering the phone) then they can be
attacked via a (1) spoof (either via harmless pranks such as 'Do you
have Prince Albert in a can? ..... Yes? Then let him out!' and 'This
is WXYZ radio. You've won $1000 if you can name this tune' OR by more
sophisticated cons for fake charities, etc.), (2) a denial of service
attack (an analogy to a SYN flood would be to program a fax machine or
computer with modem to call a number and hang up immediately once every
minute) or (3) a traffic redirection attack (either directing users to
or from a phone number. You can direct users to a phone number by
writing it down on a bathroom stall wall or placing an ad. You can
direct users away from a number by -- for example -- activating the
call forwarding feature on the phone line belonging to a popular pizza
parlor to forward the rings to another phone elsewhere.).
There are even the hated telemarketers and bill collection agencies
which use computers to help automate the work of the people in the
"boiler room" by dialing numbers, recognizing an 'answer', giving a bit
of a 'pitch' and then asking the callee to wait on the line for a human
to complete the phone call. Even when you hang up on the computer
voice, a human will generally call you back shortly, so it is clear
that they have recorded the fact that you are home and answering the
phone. I'm not sure how well they interact with answering machines and