security state

what with all the stuff in the news lately about the State spying on the internet in all sorts of deeper-than-expected ways, i thought this was interesting:

my institute was recently eaten by Mass Eye and Ear Infirmary, MEEI, a hospital. rather than fully digest us, MEEI dissolved parts of our organization and replaced with their own, so really it's more like the ant that is infected by a fluke that effectively replaces or overrides parts of her brain, or the caterpillar whose internal processes are slowly displaced by wasp larvae. i think the ant example is better.

anyways, as a part of this absorption, our computer network was transferred to the control of the MEEI network, and they are insane about security. it's as though we're at los alamos. everything is supposedly super secure. patient privacy, etc etc. as a part of this transfer of authority, every computer in the institute was infected intentionally with a suite of spyware that allows the MEEI IT people to control or observe all of our data flow. in theory. our internet is filtered, our emails are filtered (unless we take simple steps to avoid the filtering), all access to local computers is supposedly filtered. it's irritating in the all-encompassing authority they take on, at the same time that it's ridiculous how easy and convenient and necessary it is to get around everything they try to do.

one set of spyware is called "DeviceLock". you can always see it running in the background, under processes named DLservice.exe, DLtray.exe, etc. this is a program for, supposedly, ensuring that external storage devices must be encoded or they can't be used with institute systems. but i've discovered additional functions, which are mentioned in that link. there's a process running in the background, "DLSkypePlugin.exe". what does it do? who knows! let's ask DeviceLock:

""Skype" control supports blocking, allowing, auditing, shadowing and content analysis of outgoing instant messages and files as well as auditing, alerting, shadowing and content analysis (for contingent shadowing) for incoming instant messages and files. Also, supports blocking, allowing, alerting and auditing of incoming and outgoing audio/video calls;"

 where does a hospital IT department get the authority to do something like this? can someone explain to me, please?

on a final note, while most of the IT spyware can't easily be disabled - i, the virtual owner of this computer, don't have the "authority" - the DL programs can be terminated without any special privileges. an oversight, i'm sure.

ARP

One small thing, which I don't have on hand - the other night, I switched on the network monitor and saw an exchange I'd never seen before: ARKIV (my computer) sent an ARP packet to Jingping's computer, which is on the same local network - immediately, her computer responded with two UDP skype packets. ARKIV's skype was turned off. Is skype constantly checking incoming messages to see if they come from an address in its routing tables - in that case why was Jingping the only computer that got an ARP packet? Was the ARP packet sent by some active skype process? Mysteries, mysteries...

(These conversations suggest that skype knows enough to adjust its routing for LANs - so instead of IP addresses it needs to be routing to MAC addresses, or something.)

Audio

Ok, here's something slightly interesting. It has to do with Skype - the only traffic I can see here that isn't building business, or something I'm doing (webpages, ftp, updates, etc.) is Skype, so I guess that's what I live with until I go figure out something new.

Anyways, I've mentioned before about how my Skype account seems to use port 34268 to advertise its existence - UDP packets go in and out through that port, and sometimes a link gets established with one of the associated addresses, and a conversation starts - i.e. my computer gets used as a relay in the Skype network. Sometimes I see the UDP packets go out, looking for another node, and nothing comes back - they go out a few more times, and give up.

So, what I noticed is that tonight, my computer is sending RTP packets, which I haven't seen before, rather than UDP packets. RTP is apparently used for transferring video and audio, especially with VOIP applications. So, Skype is looking for someone accepting video/audio streams, trying to establish an RTP network? I have no idea.

Each of those RTP messages was reciprocated with a UDP response, by the way. Nothing else followed, however - there's a single conversation going on through Skype, leisurely exchanging TCP packets every few dozen seconds, so I would assume this is a text conversation - but it's a one-sided conversation, since my computer is communicating only with one other address! If I were relaying a conversation, I should see connections with two other hosts, not one. Maybe some sort of routing table content is being transferred, updated, etc., very slowly?

That's all I've got.

skyping

watching skype here in the lab. sending a few messages from here to jingping. interesting thing is that i don't have a direct link to her. instead, skype only reports having connections with computers at NYU - several of them, six different hosts. maybe they're using me as a relay? or, i could be part of a similar set of harvard-located hosts. here, instead of 36268 or whatever it is at home, the port being used by skype for those UDP messages is always 38253. i also see that i'm sending to each of those NYU hosts from the same port, but receiving from a different port from each one. i'm guessing that all these connections are for the same purpose, and that again for each of those users the port number is the same for all their connections.

oh well, more later. maybe something interesting will happen.

what is in my packet net?

a boring post, to start: i'm just going to go through the list of what packets i caught during a 780 second capture. skype was on, as was xdict and its incessant search for the kingsoft mothership, which is currently routed to ARKIV itself.

first on the list:
p3nlhg43c081.shr.prod.phx3.secureserver.net
robtex suggests that this is some sort of porn locus, responsible for porn spam and who knows what else. sent one packet from their http port 80 to my port 19246, which is for i don't know.

next:
multiple, periodic IGMP signals, labeled "membership report". i see this all the time, sent to 239.255.255.250. apparently, this is just to establish my presence on the network, so that the routers and other whoever know i'm here.

next:
there were 8 apparent skype contacts through port 34268. what i understand is that this is how different skype hosts find eachother. what i don't understand is why for me it's always 34268, while its always different ports for the others. could it be that for them it's always their number? maybe i'm a member of a particular skype class - the port 34268 class. really, i have no idea. these are always UDP packets, call and response, usually just once, always intiated by ARKIV. and, as i mentioned before, i see them even when skype is off, but ARKIV doesn't respond then.

next:
BROWSER: host announcement. i assume this is something like the "membership report" above, but i don't know what makes it different - ARKIV runs a browser service, and there are browser elections, to select a browser which will keep track of all the potential browsers.. argh.

next:
here is a succinct description: packet from 190.2.29.193, originating from Argentina, from port 1217 to 1434 - 1434 was the way in for something called the SQL slammer worm. SQL is a microsoft database server program - what i received was a single SSRP packet, which is a protocol specially designed for use with the SQL thingie. anyways, one hit, nothing else (presumably i am not running an SQL database server).

so really, that's it. i found a paper on principles of routing in between networks, but haven't read it yet. my learning progress is stalling.

not much

just observed a sweep from IP 66.186.59.50, "ircu.krypt.com", looking into port 1137. a bit of news suggests this is a vulnerability search. the signal is coming from an IRC line, port 6667. they must be looking at IRC logs and sweeping those addresses, since i've actually been on IRC in the last couple of weeks (and last night).

another thing, i also saw (for the first time) some nonreciprocated requests for port 34268 while skype was turned off. looking for a relay? i scanned the source and it doesn't actually seem to be a skype host, though maybe i waited too long, after they had turned it off. instead, they actually had unfiltered, closed ports 5800/5900, which are used for remote desktop viewing. also, no clue as to the OS, so i don't know what it actually is. another user? something else? it's another comcast host, presumably another user, but who knows?

i'll check it out again later.

portscan

just got my first portscan result.

it's another address in boston, using skype. it's also a comcast address, and the first 16 bits are the same as my address. the prefix of the server above it says 'needham'. i guess it's strange that it's such a similar location to mine, and i suppose i could be looking into some sort of mirror that i don't understand, but i do think it's a real, other user, somewhere here in town.

nmap saw that its http ports (80 and 443) were open, and decided that they were being used by the Skype service. i can also see that port 2265 is open, the same port from which i'm receiving packets from this computer.

the other open port (2222) is associated with a website administration program, or with who knows what else.

nmap also claims with some confidence that the computer is a pocket PC running some version of windows XP.

still, i have no idea why this computer is reflecting messages through my computer. and i still haven't figured out why there's always an explicit connection through skype with another computer - other than jingping, this is the only skype connection at the moment, so it is *the other* connection. now i'll see if it shows up again...

nmap 1

got a program called nmap, using the windows gui.

i can't really get a port scan to work on another computer. i tried to get jingping to turn off her firewall, but she said it was already off - i guess norton does its own firewall.

still, nmap has other neat functions. you can get it to do traceroute for you, along with other things, and it will hold on to all the data for you. as you do this, it creates a graphic plot of all the addresses you've been querying. if you're doing tracerouts, it plots ip paths, which is fantastic. here's what i did:

still working off the mysteries of Skype, i ran the network monitor for a few minutes, and got a list of those UDP conversations through port 34368. most of these just consist of my computer sending out a single datagram to some other address, with which i may or may not be also involved in a TCP session. a few ms later, i get a UDP back from the target. there were about 15 of these over a 5 minute period. i plugged them all into the nmap and tracerouted them (had to do this one by one, i'm going to have to get a little more sophisticated), and got back a neat plot showing how all these connections are related to me. these other IP addresses were all over the world, China, NZ, Japan, Russia, France, all over. maybe those are the supernodes, and i'm just registering with them by sending a datagram?

the plot is interesting in itself:


you can't read them but the ip address of every node along the route is listed. the maps are dynamic; you can highlight a node and all its children (those further down the route away from the center), change the center node, rotate, etc.

like i said, most of those UDP exchanges were just 2 packets, one out and one response. there were two other things that happened. one was, I sent 2 UDP packets and got back 1 RTP packet, which i think is actually a UDP packet carrying audio/video information. there wasn't anything else associated with that address, though, so i can't guess what that was about.

the other interesting thing was an instance where i sent 3 UDP packets to a certain address, with no response. i actually guessed the reason: they were being sent to jingping's laptop on campus, on the UofL wireless network, where it hasn't actually been connnected since early friday evening: i sent those UDP packets after midnight, more than 7 hours after she had disconnected.

why did this happen? one thing is, i may have left Skype running on the computer in my office, and during the day that was a connection to her laptop on the campus wireless network. or, i may have turned it off - sometimes i forget, usually i don't, but i don't usually remember if i remembered, only if i forgot (strange how that works). at any rate, for some reason, my computer, being connected with my Skype account, thought to check to see if that UofL address was still on, despite the fact that the account it had been associated with was now associated with another IP address. this doesn't make a lot of sense to me. some sort of cleanup work on Skype's part?

mysteries, mysteries.

skype port? broadcasts?

ok, very briefly because it's late.

if i leave the network monitor on for a while, it lists lots and lots of conversations between ARKIV (my computer) and other addresses out there in the world. most of these are UDP packets, but not all. of the ones that are UDP packets, i'm pretty sure that they're all associated with Skype. here is how i know:

the monitor does show when conversations are known to be controlled by a particular process like Skype. so, tonight, i record for a while, and i see two other addresses associated with Skype. one is jingping, i know, because tracert tells me that it's an insight address routed through Atlanta, and i already know that's our service in louisville. the other is somebody in new bedford MA, still in the comcast network. i don't know what that is.

anyways, so i can see jingping's IP address. it also shows up in the 'unknown' associated list of all those UDP conversations, with a different port number, 34268. all the other UDP conversations (most - i didn't look at each one) are also going to port 34268, so i deduce that they must also be associated with Skype.

so, apparently Skype is going to be an internet learning tool for me. it's very mysterious. are these other Skype users, using ARKIV as a waypoint for finding other users? i think that's what a supernode does, but from what i've read supernodes should have many, many more connections. so, i still don't know what this is all about, and skype's operations are kind of trade secrets which are hard to research online. still, i'm sure there's plenty out there for me to figure out.

okay, so there, i learned that i can identify a process by its port number. or, at least, i deduced it. it may be wrong.

ports and NAT

ok, so i've been kind of curious as to what a port is. i still don't really know, but i think it's kind of like an address for a specific function within a computer. a computer has lots of ports. they're not physical things, more like indices for input and output.

anyway, i was reading about network address translation (NAT), and a part of understanding it requires the concept of ports. NAT is where a computer locally has one IP address, but to the rest of the internet it appears to have a different IP address, and possibly the same address as lots of other computers that are on the same local network. this happens because they're all on a private network, say, and they're all using a router to send info out into the internet, and get info back out of it. the router knows all of the computers on the private network by their private IP addresses, and it assigns each of these to a specific port number for its own IP address (the router being just another computer in the network).

so, when a computer on the private network sends a message out into the internet, its private IP address gets changed ('translated') into the IP address of the router plus a specific port number. incoming messages meant for that computer must have the correct port number; basically, for the router, port numbers refer to computers on the private network.

but that's not enough, because each of those computers is using different ports to do different jobs with different targets on the network: one port keeps in touch with the Skype supernode, one port is getting data for a file i'm downloading, and another port is sending the info that i'm typing into this blogger.com window right now. so, actually, the router has to assign a different port number to each port on each computer on the private network; so, for the router, a specific port number will refer to a specific port on a specific computer on the private network.

i'm pretty sure this is all true for the protocols that have to do with sending and receiving files. i still need to learn about protocols, but i think there are also protocols for sending packets to all computers on a network, so maybe you wouldn't need to know their port numbers exactly to do that. not sure.

anyways, there's some stuff about ports.

microsoft network monitor

oh, this is even better. i figured there must be programs for watching network activity in real time. i just googled "network monitor", and this was the first thing on the list: "microsoft network monitor". hey! i thought i'd see what it did.

what it does is exactly what i thought it did, and more. it keeps track of all the packets going in and out of the computer over a period of time. it also automatically bins these packets according to 'conversation', which is the set of [origin destination] that describes all of them. so, all the packets i send to jingping through skype fall in one bin, and all the ones she sends to me fall in another bin, for example.

last night i saw a couple of strange addresses communicating with my computer. i had turned off the browser, skype, and the chinese dictionary (which has some sort of homing beacon to beijing in it), but i still saw those packets arriving. where were they coming from? i don't know, except that one origin was in china (ningbo; 'zooz.org') and the other in australia (forgot the city). maybe my computer is a zombie! i will solve this mystery..

now, i need to learn more about packets and protocols.

netstat

okay, netstat is neat. it shows you a list of all the IP addresses to which your computer is connected by a port. i haven't figured out what exactly a port is yet, but i think it's just like some sort of i/o index for the computer. what's more neat is that if you type netstat -b, it will show you the list along with the applications associated with each. for me, this basically means firefox (chrome boo) or skype.

so, from this i have learned something interesting about skype. if you're just connected to it, you'll see some foreign address that's unfamiliar - i guess it's just like a neutral relay node or something, which you use to connect to other people. if you're currently talking with someone, in chat or phone, you can actually see their address directly. this is why skype is a 'peer-to-peer' service: you connect directly with the other person.