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Stopping NetBIOS Spam?
MoonFacedAssassin asks: "I woke up this morning to find that my computer had a Windows messaging pop-up window with an advertisement about getting diplomas and degrees. I was quite shocked to find that my Bellsouth DSL IP address had been spammed. Has this happened to anyone else? Other than closing off the port which this can come through, are there any other ways to block this spam? And, how responsible is Bellsouth (or any ISP for that matter) in handling issues like this?"
Are you new?
Seems to me that restricting the port would be the sane method of preventing outside persons from exploiting your system. The same as any other service on any other port.
i hate pansy republicans
Don't run windows ...
I got one of these just the other day.
I believe shutting down the messenger service will stop them.
On Windows NT/2000/XP, stop the messaging service and enjoy ;-)
TechTV covered this earlier this year so you might want to read their breif article for more information.
Basically, they're port scanning for open port 139s and spam IP that comes up positive. Either turn off the messenger service in services or install a firewall/router and block incoming tcp connections on port 139 (NetBIOS).
While you're at it, turn off the remote registry service...
Block the port. To be honest, I can't understand why you would leave any ports open, when on an always-on connection, with a static IP address. Unless you have a service running on a port, that you want it to be public accessible, all other ports should be blocked and stealth. Experience says this is especially true for netbios ports...
As for the second part, you cannot count on an ISP's usage terms to protect you from malicious acts. For good or for bad, they sell access services, not security services.
Common sense today is to use a firewallson all home connections (e.g. Zonealarm). That would have prevented the NetBios 'hack' you experienced through the netbios port.
'A lie if repeated often enough, becomes the truth.' - Goebbels
Block the port, use zone alarm, or (shameless plug) install this firewall
-John
Funny, today I got one of these for the first time. My first thought was, "Why didn't somebody think of this before?"
The fix for this should be either at the OS or user level. Personal firewalls are not hard to find, and inexpensive compared to the cost of net access. If ISP's start blocking every port that could be abused, sooner or later we'll ALL be turned into one-way consumers.
I assume that you don't want to block the port because you want to have fully functional file sharing with people you know in your vicinity.
I think that what you probably want is to block the port to all IP addresses that are not in your subnet (local network). Therefore, if anyone spams you in the future, they have to be inside BellSouth, and you can (probably) get their account closed. But chances are, there's not gonna be anyone spamming like that from inside BellSouth.
That happend to me around Midnight on Monday. I shut off the "Messenger" service in WinXP (although 2k has the same service) and I still had NetBIOS running without getting network popups (who uses them anyways?)
Hope this helps.
P.S. The "Messenger" service in the Services list has nothing to do with Windows/MSN Messenger, so please don't confuse the two. ^_^
"Black holes are where God divided by zero." - Steve Wright
Dear Slashdot,
When I go to work, I leave my front door unlocked and slightly ajar. The other day when I got back, I found vagrants sleeping on my sofa and defecating in my sink. Other than closing and locking my door when I leave, how can I get rid of them? Has this ever happened to you? Also, can I sue my landlord over this? Thanks.
Yours,
Confused in Cleveland
Yesterday, I also saw a stupid diploma Windows Messenger spam, at school. It claimed, as I recall, to come from WEBPOPUP02. In any case, I'm hoping that the school takes account of that and does the obvious (blocks off the port to people outside the network).
true && more || less
I have 2 Windows computers at home that have public static IPs. Instead of using my DSL router on the windows machines, I've given them local IP addresses (192.168.*.*) and route them through my Linux server. There I've put up an iptables firewall with DNAT and SNAT, so that when the windows computers are routed through the firewall, they get their public IPs assigned to them, and you can access the computers from the outside with the public IPs. On the Linux router I've added tons of rules, and one of the most important rule is the one that blocks ports 0-1024 on all windows machines. All important ports are usually below 1024, so I can basically run filesharing, etc. without having to worry about users accessing the files from the Internet (or accessing windows messaging). However, since all ports above 1024 are unblocked, and have a public IP due to the SNAT, the users on the windows machines can use P2P apps, play games online, etc. since their machines are accessible from the outside. This has worked extremely well for a long time, no need for firewalls on the windows boxes (like Norton Internet Security). I haven't experienced any viruses, hackers or unwanted pr0n sent to the printers because of open ports. :-)
Spam Takes New Form
Most decent DSL/CABLE Modem providers block the netbios ports these days...thats just sad that they have those ports open and avialable for traffic on thier network.
Hint: Get a linksys router and those ports will no longer be available for spam...
Hint2: Don't leave windows machine hanging on the wire like that unless they are memebers of NT domain. It will stepup the security of the Netbios connections.
Hint3: Not ever leave an improperly secured NT machine hanging on the wire like that....
Hint4: see hint 1
Power Corrupts,Absolute Power Corrupts Absolutely, leaving one person(group)in charge is absolutely corrupt.
NET STOP MESSENGER
To make sure it doesn't restart next time you reboot, go into Control Panel, find the Services applet. Set the Messenger service to startup settings of "Manual" or "Disabled" (as opposed to "Automatic" which restarts it at every boot).
That works for NT, 2000 and XP. If you are still running 95/98/Me, then may god have mercy on your soul.
We're getting into topic creep, but I guess nobody will mind because the original topic was so silly....;-)
That is a different kind of RPC's, that pre-date Windows. It does not use 135. Microsoft usually screws things up the first time, and reinvents it several times after. This is one of them.
The RPC stuff in SAMBA dates from the old LAN Manager days, and ran over the same port the file and print sharing did (139). This stuff existed in the days of DOS and Win16, long before COM and DCOM ever existed. It worked well enough to add a few functions to this subsystem. It had lots of problems: it was not easily extensible, couldn't be run on top of other protocols, and was not object oriented, etc.
Later, when Microsoft was building what became COM and DCOM (and what was then called OLE), they realized they needed a more robust RPC mechanism. They decided to use DCE RPC, theoretically an open standard. It is what DCOM is built on top of.
SAMBA continues to use the "old" RPC mechanism (for compatibility), and therefore does not use this port. If you look into the API documentation for the API's exposed on top of these RPC's, you'll see Microsoft deprecates many of them.
BTW: I didn't write it, I copied and pasted from their site.
THERE IS NO DATA. THERE IS O
This stupid question (block the port, be done with it) has given me a potentially useful idea.
How hard would it be to send a message back to the boxes that have some code red or similar virus. Basically you ask my web server for c:/scripts/something, you get a Windows message back informing you in no uncertain terms that your box is infected and the OS needs to be reinstalled.
This isn't an attack, but if enough people did it (just one message per infection attempt) people would soon be forced to do something because of the barrage of messages. And the people who let their boxes REMAIN infected with a virus that's been out in the wild for over a year are hardly the type of people to have locked down port 139.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
How about trying to provide some assistance...
I received two of these messages within the last month. The first puzzled me, but only briefly, since I was ragingly drunk. The second one bothered me however. It didn't seem right to me that someone should be able to do message me like that without my explicitly allowing it (and really, how can they give you a PHD or University Degree by filling out a short 5 minute form?! It's crazy.)
In any case, my first inclination was to try and find some sort of messenging service in Win2k and turn it off, which I promptly did. But isn't this just applying a bandaid to a scratch on your arm, while your entrails are spilling out of your abdomen? I mean, this must be a sign that my system is not that secure.
But is it really true, according to one poster, that if I share a drive or a printer I have been "HACKED ALREADY"? And whether I am or not, aren't there other choices besides reformatting, changing ISPs, blocking lots of ports useful to me, or just unplugging my box? I have to say poster, that you were a little curt.
In any case, I am looking for (relative)layman's advice that isn't as drastic and cynical as this (can I find such a advice on Slashdot?) for the Win2k user; also, I would appreciate some suggestions for software a) to help clean up my system if it needs it, b) to divine the actual level of current security (or lack thereof), c)to create the firewall that so many people tell me I need. Share/freeware would also be nice on this college student's budget.
Thank you for your patience and any help is greatly appreciated.
If I may ask, why are you relying on the ISP to handle this?
It's an unfortunate consequence of the way the network is that one should be watching over one's own machines.
"The Devil does not know a lot because He's the Devil, He knows a lot because he's old." -- unknown
Only I was on AOL...Strange...
No TiVo and no caffeine make me something something...
OK, please do not regard this as bashing. It's just the correct answer to anyone with this problem - if you don't like it, the problem is not in the answer.
NETBIOS CANNOT BE SECURED. If you leave your netbios ports open, you can be cracked to such a degree that it will be impossible for anyone other than a forensic analyst (who will boot from a linux or BSD boot disk) to detect. Netbios is only a viable solution on TRUSTED networks, which the Internet isn't, by definition.
YOU ARE PROBABLY OWNED. Your machine is most likely already completely compromised, and is happily working on cracking RC5 ciphers for somebody you've never met. See the honeynet project for more information (incidentally, one of the founders of honeynet reportedly got cracked by el8; everybody can make mistakes).
YOUR BEST OPTION IS TO FORMAT YOUR HARD DRIVE. The fastest, most reliable way to remove any possibility of a problem is to reload your system from a read-only media - i.e. your windows distribution disk. You must scrub the hard drive first, though; there are programs that can survive windows reinstallation unless this step is taken. You must also disconnect your Internet connection until you have a firewall running, to be absolutely safe; you should buy the firewall or get a friend with a more secure system to download one for you, since anything you download with your machine is suspect.
Hope this helped!
(You will have to graduate from newbie status in order to take advantage of my advice. This means that you will have to climb the learning curve and actually go read some stuff. You can spend a chunk of cash on products to avoid doing just that, but that's much less fun.)
a d_license.htm. You will occasionally find that it interferese with pages that make heavy use of Javascript, but you can turn it off when needed. The added protection from annoying web sites is worth the small inconvenience it may sometimes cause.
If you're doing things like turning on file sharing or sharing printers, it's (supposedly) very easy to hack you. I say supposedly only because I haven't actually tried this. It's such an infamous hole though that I do believe it. To turn this off, unbind the NetBIOS protocol from the modem/network card that connects you to the Internet. In Windows 2000, that you means you go to the Properties for your network connection (in the Control Panel) and uncheck the 'File and Printer Sharing for Microsoft Networks' option. (It's very easy to fix this in Win9x too using roughly the same technique.) You may have to reboot, I don't recall. That problem will then be solved.
Now to protect yourself from other intrusions and threats.
If you're just running a dial-up connection and don't leave your machine on the network for extended periods of time, then a product like ZoneAlarm (www.zonelabs.com - look for the free version) will serve you well. Actually, it serves you well in two ways: 1) it protects your machine from the outside world coming into your machine in an unauthorized fashion and 2) it protects adware on your machine from phoning home without your permission (actually it prevents everything from using the Internet until you grant permission, not just adware). This is sufficient for dialup.
For broadband users and users who want to leave their machine on the Internet for extended periods of time (more than a couple hours at a time), I recommend using an honest to goodness separate firewall. There is a lot that can be said about this, far more than I know really, but I well give you a couple pointers.
First of all, one of your options is to use a second PC as the firewall. It will need to have 2 network cards, you will need a router or hub for your home LAN, and you will have to get the cable modem (or DSL for that matter; with which I have no experience - shouldn't be too hard) working with that extra PC (via Windows would be easiest to start with). Once that's setup, go grab a Linux distribution like IPCop (or SmoothWall - they're very similar, in fact they were the same product at one time), and install it on that PC. It will require that you reformat the hard drive, so don't plan on storing any files on it. A small hard drive is sufficient. There are FAQs and forums on the IPCop and SmoothWall sites that will help get you setup.
Your second option in the category of 'real protection' (for home users anyway) is to just go buy a hardware firewall. So instead of a second PC, you just go buy a device that does essentially the same thing. I won't go into detail on these as I have no experience with them. I just thought you should know about them.
Two last points:
-PLEASE keep a current anti-virus product actively running on your machine and keep it up to date. If you need a free one, go to http://www.grisoft.com to get the free personal version of the AVG anti-virus product. This one has saved my butt several times from several infections. It may or may not be the best product out there, but it works for me.
-To protect yourself from browser window popups and other shenanigans, go grab WebWasher at http://www.webwasher.com/en/products/wwash/downlo
As always, this advice is just a starting point. Today's perfect security solution may be an open door tomorrow. It's up to you to keep yourself informed and to take action when problems arise.
Good luck and have fun!
Please mod this post only if you think others should/n't read this. I have enough ego^H^H^Hkarma. Thanks!
Quit whining, the easy way to fix it is to block the port, no 'but's. The proper way would be to get rid of NetBIOS or whatever messaging device is being abused.
-Billco, Fnarg.com
It happened here just this morning. Spammers suck. Congress sucks for not banning advertising by email. Oh well, back to life.. back to reality.
Ouch! The truth hurts!
1. Click Start Menu 2. Click Settings 3. Click Control Panel 4. Click Administrative Tools 5. Click Services 6. Find Messenger in list, view properties 7. Change Startup Type to Disabled 8. Click OK 9... 10. Profit! NOTE: This has nothing to do with MSN Messenger it's purely the "NET SEND" command.
http://www.techtv.com/screensavers/answerstips/sto ry/0,24330,3374542,00.html
This firewall distro works great. I know everyone likes Freesco, and I use that too on occasion, but I've had the NetBSD firewall running at one of my client's offices for about a year and a half, and it's given me absolutely no trouble at all. Several people in our LUG use it as well.
:-)
Great product
Need a Linux consultant in New Orleans?
Please, windows users, don't disable windows messenging, it can't hurt by itself, and it's very convenient to explain to the people filling my snort log that they are infected by a virus (and are going to be nuked BTW).
First of all, I'm not an anoymous coward. I simply don't want to sign up for another junk mailing list by signing up "correctly" This does not make me a coward, this makes slashdot rude for forcing me to either say nothing, post to "anonymous coward" or give them information they 'need' only because its a possible profit generator though they will not have to deal with the consequences. If they want to pay me for the use of my information fine, if they want to deal with all the crap that will surely come my way (meaning someone from slashdot manually deals with my junk email onsite at my office everyday, that's fine too. If they don't offer those options, I'm not a coward for keeping my information to myself. That said, lets move on...
.dll file goes bad on your computer, a large network address bank in Florida may be the ones suffering the consequeses. Thus, computers and cars are different and the idea that computers are harmelss toys and that all trouble with them is a personal, local experience couldn't be more wrong. These harmelss toys we have at home are in a big way responcible for the billions of dollars lost due to worms and viruses. How is this possible? Well, since we're talking about a network, what happens at one end can directly impact the other. If a home computer doesn't take basic security precausions, the corporate/government/bank/whatever computer at the other can be taken down. This has happend before. The internet worm all the way back I think 10 years ago, nimda, code red, I love you, etc.,... are all examples of how fast and pervasive worms and viruses can be with the smorgasboard of open computers out there. If these open computers had simple basic protection, these worldwide attacks wouldn't have spread so fast and wouldn't continue to survive. Afterall, if everyone had the deffinitions for the nimda virus, it couldn't spread. Thus, since it continues, we have proof there are machines without nimda av deffinitions out there. After a year, that is not only irresponcible, but is boardering on criminial.
Reguarding ports 135-139 being open to the internet. Lets make an analogy: computers to cars. With cars, can a 5 year old get in a drive whenever they want or do you need to be at least 16 in most states? If you are caught driving without a licence, do you go on your way after the officer apoligizes for having the gaul to expect you to have a licence or do you get a ticket/get arrested? If you get in an accident, are you expeted to have insurance or is saying you are sorry using the fact you didn't understand as your excuse? Do you get to walk away from the next accident for the same reason or are the authorities and your insurance company going to be a little miffed with you? What about the other car? Did they say "no problem, I'll pay for everything, you didn't know any better." or are they really upset since their car is totaled and their rates will probably go up through no fault of their own?
Where am I going with this analogy? Well, lets face facts. Computers and cars are different in the sense that car trouble is obvious and in your face whereas computer trouble is usually too nebulous for most of us to figure out. When your carberator on your car goes bad, your car dies and won't start. When a certain
Its bad enough we have to deal with major vendors caring not about secure coding so they can make sure to beat the competition to the market with their new product or course to be advertised as 'secure', the last thing we need is the masses absolving themselves of responsibility simply to avoid learning the basic requisite computer knowledge.
Remember the car? We had to get licences right? If we don't start educating ourselves or decline from using what we se as a toy, but what in reality is a dangerous tool of high technology - just like a car, we will only make the problem worse.
A computer is a complex piece of equipment. Its not something you can expect to just know how to use simply because you signed a check to purchase the equipment. Either make sure you cover you bases by asking or hiring somebody to consult you, then REALLY and ACTUALLAY follow their advice, don't dog around, be lazy and think "oh, it won't be me, someone else will get hacked" or think "I don't really need to do that, that would cost 100 dollars, he/she must be wrong." Remember - if you don't know why you should block port 135 at the firewall, you have no place to say anything about anyone being right or wrong about computer security - you are if anything in learning mode.
So... lets get out there and either learn or find someone who knows, take a look at our networks and plug the holes! There is no excuse for not doing so. Its the wild west out there - more reason than ever not to hedge your bets or hope you won't be a victim or think it someone elses problem. Just like driving, we share the road, so your skill driving the car is absolutly my concern - I'm not the a$$ if you think otherwise.
Justin Moebus
Why would you allow NetBIOS to be open? Um hello???
I see a lot of posts like, I got one last night, ect.
Also I first just noticed it on my girlfriend's familly computer, zone alarm kept popping up, someone is trying to access net bios services. I did a tracert and it was from a NY ISP.
I wrote down the addresses of the attempted accesser (don;t want to offend any good hackers here) for later exploration (the deafault win98 install doesn't have the tools I wanted). Anyway is all this activity recently because of some as of yet undiscovered worm?, is it a worm that has been around that is starting to do this? have lots of attempted uninvited resource accessing people just decided it would be fun to try out (perhaps rotting flesh 1337 krew just posted a file or tool to do this?). Or is this something that has always happened a lot?
BTW, this was a dynamic dial-up account, not an always on DSL/cable.
Wow, sent an e-mail as suggested when clicking on "use classic" banner, and got a fast response that addressed my msg
install smoothwall on an old machine in front of your home computers and relax.
Large print giveth, and the small print taketh away
Get the freeware program ZoneAlarm. It will protect your computer from most things, and a good anti-virus (AVG is a good free one). Bothe of these programs are available on Cnet's download database, just search for them. Also, unless you need your computer to be on all the time, turn it off. This will lower your exposure, and your computer will have less "events" to deal with. Hope this helps.
"/. =
You give most of it away in your submission. You use the word 'Windows', and five will get you ten you have a lot of dumb junk like Java, VBScript, web scripting, JavaScript and stuff like that turned on all over the place.
NetBIOS spamming? Check the nut behind the wheel first before you go shouting 'wolf'.
It is as simple as that, just unbind the netbios protocol from the tcp/ip stack that is linked to the internetet.
NT4: control panel -> network -> services -> services, just make sure under your internet ip (dail up adpater) nothing else then tcp/ip is checked.
win2000: network -> make sure only tcp/ip is checked.
Stopping the messager services will stop the spam, an leaves your PC open to the internet. But it helps against BOFH.
Well folks. I wonder what kinds of jerks we have around. After all these Microsoft injected security risks of the recent past, why would any sane mind still run a non-firewalled, unpatched M$ machine on a permanent connection? If you do, you get what you deserve. Get a life dudes.
I've also had the same problem. I appreciate all the helpful information from people who don't act like pompous SOB's.
So to everyone who gave great tips - THANK YOU!!!
Sincerely,
Earl
Omaha, NE
I'm actually quite happy that my ISP (Optimum Online) doesn't block ports such as Netbios. Some other ISPs have blocked ports such as the ports for Gnutella, Kazaa, etc. While my ISP technically doesn't want you to be a server of any kind (as stated in their EULA), they never respond to a lone user running an FTP to access their files from a remote location. As stated by many before me, it shouldn't be the ISP's responsibility, but the end user's. Once they turn off netbios, they'll start putting obscure caps on (my friend has a 15k upload because of one). It should only be the ISP's responsibility if it greatly diminishes service. In the case of my friend, who installed IIS on his Windoze box, some spammers exploited his SMTP server and sent out thousands of spams from his computer which brought many local clients to a complete slowdown. The ISP notified him and let him know. The ISP should be your friend, but not restrict you.
hip hip hooray!!! let the spammers work for us (opensource users) by annoying the hell out of microsoft users
2 085-10122374. html
r od uctdoc/en/default.asp?url=/windowsxp/home/using/pr oductdoc/en/net_send.asp
GO yonder and spam microsoft's customers to kingdom come...
Downloads
http://downloads-zdnet.com.com/3000-
http://www.microsoft.com/windowsxp/home/using/p