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How Can I Tell If My Computer Is Part of a Botnet? 491

ashraya writes "My father (not too computer literate) has a desktop and a laptop both running Windows in his network back in Hyderabad, India. I set up a Linksys router for him to use with his broadband service. For some reason, he reset the config on the Linksys, and connected it up without wireless security, and also with the default admin password for some time. As you would expect, both of the Windows computers got 'slow,' and the desktop stopped connecting to the internet completely for some reason. As I logged in remotely to 'fix' things, I noticed on the Linksys' log that the laptop was making seemingly random connections to high-numbered ports on various IPs. I did an nslookup on the IPs to see that they were all either in Canada or US, with Comcast and other ISP addresses. Is that a sign that the computers were in a botnet? Are the other hosts part of the botnet too? (I have since rebuilt the Windows hosts, and these connections are not happening now. I have also secured the Linksys.)"
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How Can I Tell If My Computer Is Part of a Botnet?

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  • by ls671 ( 1122017 ) * on Thursday August 06, 2009 @04:59PM (#28978743) Homepage

    Well the only fool proof way that I can envision is the following

    1) Plug you father computer into a HUB ( not a switch, unless it has a special port for this usage)

    2) Plug the router into this HUB

    3) Plug a Linux machine into the HUB and use tcpdump to examine traffic.

    This is what security experts do.

    • by jspenguin1 ( 883588 ) <> on Thursday August 06, 2009 @05:02PM (#28978793) Homepage
      You can also use a host with two interfaces and set up bridging or routing with NAT. If you are running custom firmware you can do this straight on the router itself.
      • by ls671 ( 1122017 ) * on Thursday August 06, 2009 @05:14PM (#28978947) Homepage

        Agreed, I do it from my Linux router which I assume is not owned.

        It is nevertheless better to reserve a machine on your network for just this usage. Nothing installed on it but tcpdump and similar tools. You should even disconnect than machine from the network when not in use. Again, that's what security expert firms do.

        The important point is to be confident than what you are looking at is not coming from something that is already owned. Many root kits modify netstat, tcpdump and the like... ;-)

        • by B'Trey ( 111263 ) on Thursday August 06, 2009 @06:02PM (#28979547)

          It is nevertheless better to reserve a machine on your network for just this usage. Nothing installed on it but tcpdump and similar tools.

          Or boot from a Linux Live CD.

          Also, some switches support spanning ports, which will allow you to sniff the traffic on another port. Your typical home network dumb switch probably doesn't support this, but if you have temporary access to a higher end switch, it makes such tasks much easier. You can pick up older switches that support this fairly cheap on Ebay, although you probably won't want to spend the money for a one-time usage.

        • by Lord Bitman ( 95493 ) on Friday August 07, 2009 @06:25AM (#28984125) Homepage

          Indeed. I don't know why security companies don't aggressively push this kind of product for home use- sounds like a win-win for them: sell the consumer an expensive physical box /and/ charge them for monthly firmware updates. Special bonus: An external box would actually /work/ (and with the aid of a USB connection, it could boot into its own environment to do scans) Just for fun, you could throw in a "real" firewall.

          So then you'd provide:
            - Network monitoring for statistical "suspicious packet" analysis
            - Completely detached scanning which doesn't just nicely ask an infected system whether it's infected or not
            - Hardware firewall
            - A solution which potentially /works/, rather than one which is guaranteed not to

          Yet everything I've ever seen pushed to home users has been a software-only package, or just a firewall. When will I be able to tell my mom to "go buy a Norton ActuallyWorX box and plug it between your computer and router"?

        • Re: (Score:3, Insightful)

          by BobMcD ( 601576 )

          You should even disconnect than machine from the network when not in use.

          Or add a read-only end to your patch cable - []

          I keep one in my black bag. Allows me to supervise any network without anyone knowing I'm even there, because it is impossible (electrically) for my NIC to respond...

          With such wiring, you're effectively immune to Virii and the like, unless they're some sort of magical single-packet thing...

      • by JohnnyComeLately ( 725958 ) on Thursday August 06, 2009 @05:52PM (#28979433) Homepage Journal
        I remember from my Sun Solaris 8 network or sys admin class that they said the system will automatically configure itself as a gateway between two network cards. When my son gets old enough to start surfing on his own, it's what I intend to do. I've got an old Solaris 8 machine on an Ultra 10. I can put it out in the garage (next to the cable modem) and have it be a physical hop between the cable modem and Dual Band WiFi router.
        • Re: (Score:3, Informative)

          by mysidia ( 191772 )

          It's true, by default Solaris has IP forwarding enabled between all interfaces.

          You can turn it off, by using: ndd -set /dev/ip ip_forwarding 0

          On most Linux systems, it's off by default, but you can enable it by doing echo 'net.ipv4.ip_forward = 1' >> /etc/sysctl.conf
          sysctl -p

          Or temporarily by doing sysctl -w net.ipv4.ip_forwarding=1

          This is not really an advantage of Solaris that it's enabled by default, but a security risk.

          My suggestion would be to instead use a cheap old x86 PC and instal

    • by neowolf ( 173735 ) on Thursday August 06, 2009 @05:12PM (#28978933)

      The hard part nowadays (although maybe not a problem in India) is actually finding a HUB. It is very difficult to actually buy a hub anymore, and most "hubs" sold in the US anyway are actually low-end unmanaged switches, so you can't sniff traffic on them.

      In answer to the question though (I'm sure redundant at this point) is: YES- they are probably part of at least one bot-net, and are probably infected with all sorts of other nastiness. The best thing to do is re-secure the wireless router, and the all-too-often-recommended reformat and re-install of Windows. I wouldn't even try to salvage the current installs at this point.

      • by sofar ( 317980 ) on Thursday August 06, 2009 @05:20PM (#28979063) Homepage

        You don't need a HUB at all. Linux bridging allows you to use two ports on a system 'as a HUB', while still providing you with the ability to tcpdump a port on the bridge. You just add both interfaces to your bridge and stick the linux bridge in between the real router and the infected machine. Only thing needed is a linux system with 2 physical ethernet ports.

        • by ls671 ( 1122017 ) *

          Yeah, this works too, not as effective in order to snoop-in without being detected, hmmm. I mean without disrupting normal business operation but it would work for his computer father.

          Dedicated port on switches are more standard for security audits. You just plug a laptop with one network interface on it et voila.

          Also, routing traffic through your Linux changes something to the network topology so you are actually interfering with the network compared to stealthily listening.

          • by sofar ( 317980 )

            if you're paranoid, sure. Don't use this method to 'snoop' data where you are not allowed.

            For a sysadmin, this is a great way to isolate a machine without touching it. I doubt a botnet is smart enough to detect MAC address changes...

          • it would work for his computer father.

            What?? His father is a computer? Then I bet the father is part of the botnet too! Oh noes!

      • by ls671 ( 1122017 ) *

        Then you are stuck with buying a slightly more expensive switch with a special broadcast (HUB like) port designed for just this usage. Many have those. Most corporate switches have them in order to enable security audits or other network surveillance tools.

        • by DarkOx ( 621550 )

          Most switch used in a business should support arbitrary port mirroring. That is you can duplicate the input out put or both of any port to any of the the other ports. Good equipment will even support remote mirroring and will be able to encapsulate the traffic on one port and send it all to some other location of your selection.

      • Re: (Score:2, Interesting)

        by bpfinn ( 557273 )
        You could also get a network tap. I've had my eye on the Teeny Tap [] for a while.
      • There are other ways (as mentioned, computers set up as man in the middle) or managed switches. However, somewhere in storage is my old hub, just in case. Don't forget that many routers are actually also managed switches, your router may have the ability to do this as well. Or look for a cheap one that can act like this, consumer targeted routers are cheaper than most managed switches (and likely much slower, but for this kind of thing they should be fine).

    • by endikos ( 195750 ) * <> on Thursday August 06, 2009 @05:14PM (#28978951)

      Or they use a "real" switch that has port mirroring, or a passive ethernet tap [].

      • by ls671 ( 1122017 ) *

        >> 1) Plug you father computer into a HUB
        >> ( not a switch, UNLESS it has a SPECIAL PORT for this usage)

        > Or they use a "real" switch that has port mirroring, or a passive ethernet tap [].

        Thanks ! ;-)))

    • by iamhigh ( 1252742 ) on Thursday August 06, 2009 @05:15PM (#28978965)

      Well the only fool proof way

      If that sentence doesn't end with "from orbit" and have "nuke it" in there somewhere it just isn't true!

    • Heck why can't you just run Ethereal on the local PC and just monitor what comes and goes from the local interface?
      • by DarkOx ( 621550 )

        For the most part he probably could do that; but a well enough designed root kit could possibly replace the operating system interfaces libcap uses and not report its own traffic. That is certainly not your run of the mill botnet software or malware but stuff that can do that sorta thing does exist.

    • Or use a real switch with a port mirroring option. Or use wireshark installed locally. Regardless, this is remote support so he'll probably have to use some local options and the linksys log, netstat, etc. If he can manage a capture with wireshark then he's 99% of the way there.

    • by krappie ( 172561 )

      Are we assuming that the packets will be obvious IRC packets or something? It would be suggestive of a botnet if lots of traffic was moving while the computer was idle, but that could always be background programs downloading updates or whatever. If a botnet used any sort of encryption, or even a binary protocol instead of ascii, it could be extremely difficult to tell it's a botnet by just looking at packets.

    • Why not just tcpdump from the father computer or use something like wireshark?
    • by taskiss ( 94652 ) on Thursday August 06, 2009 @05:47PM (#28979387)

      Is a father computer anything like a mother board?

    • by u38cg ( 607297 ) <> on Friday August 07, 2009 @03:24AM (#28983285) Homepage
      My foolproof method:
      1. Is it running Windows?
      2. Is it connected to the Internet?

      If the answer to both your questions is "Yes", then you are most likely part of a botnet. This advice is free of charge.

  • by eldavojohn ( 898314 ) * <(eldavojohn) (at) (> on Thursday August 06, 2009 @05:00PM (#28978755) Journal

    As you would expect, both of the Windows computers got 'slow', and the desktop stopped connecting to the internet completely for some reason. As I logged in remotely to 'fix' things ...

    Quick question, how did you log into his desktop remotely if it "stopped connecting to the internet completely for some reason?"

    If all you did was reset the hosts file, it will be back sometime. Somewhere, probably in multiple places on that hard drive, is an executable waiting to be run. It's probably infected some inane looking routine Windows system file that occasionally runs and when that happens your host file will magically change again.

    I could recommend you do a netstat but what's the point? Any botnet today would know how to elude that or run as part of a system routine. If the bot is serious enough, your best bet might be to save the data and just do a routine re-install. You know on my parent's WinXP machine, I do that everytime I'm home for christmas. Then I patch it as far as I can over their 56k modem.

    Odds are high your dad's machine is still infected and I would also suspect your machine as being potentially compromised if you connected using Windows remote desktop. Call me overly cautious but I don't take chances with Windows.

    You can run all the programs you want (Bothunter [], Symantic, AVG, AdAware, etc.) but in the end there's no guarantee although BotHunter's probably your best bet.

    The best thing to do is educate your dad. If he has a valid copy of Windows, spend time with him to show him how to go to IE and click Tools -> Update Windows then select all updates. Remind him periodically when you talk to him--especially if he does any banking or commerce online!

  • idiot lights (Score:2, Informative)

    by v1 ( 525388 )

    look at the activity lights on the whatever you have for networking equipment. If the activity lights go ape after the system comes up, and stays that way, back up what's safe and reload it.

  • Assume it is .. (Score:5, Interesting)

    by Brigadier ( 12956 ) on Thursday August 06, 2009 @05:06PM (#28978849)

    Overseeing a small office lan, I've come to the conclusion that you will be infected whether you like to or not. Regardless of how much you threaten users. I've resorted to using an drive image (paragon) saved on a drive partition which saves the system in a uninfected state. As soon as a user goes 'uh ooh' or complains of slowness I restore the image (keep in mind data is stored on a server which is backed up and scanned on which no apps are allowed to run). I also run a combination of ccleaner, spybot s&d and windows defender.

    In addition I check the network once a week for mail or ftp sockets ( evidence there is a bot net at work). So far this has been the easiest way to stay on top.

    • by realmolo ( 574068 ) on Thursday August 06, 2009 @05:19PM (#28979027)

      You're doing it wrong.

      You need an IDS/IPS system like a Fortigate or ASA that scans all incoming/outgoing packets for viruses/spyware/whatever, and blocks them before they get to the computer (as well as performing standard firewall duties like NAT and traffic filtering). You need Websense Express (or something similar) to block access to malicious websites (and inappropriate websites, which are often malicious anyway). You need to take away the Local Administrator rights from every user on the network, and use Group Policy to a) lock down Internet Explorer, and b) prevent them from installing any software and c)making any system changes.

      This is all easy to do. Why aren't you doing it? For a small office, it wouldn't even be expensive.

      • by Brigadier ( 12956 ) on Thursday August 06, 2009 @05:44PM (#28979333)

        All great points, here are mine.

        1.) We are an architecture office which runs AutoCAD problem is this requires Power User group membership in order to run. (also on windows even without admin privs malicious software can infect.

        2.) Unfortunately any expense is an expense, (economy doesn't help.) This is why you will note all my network software is freeware.

        3.) My most malicious user is the owner of the company, who insist on having admin privies ( he equates user authority to company hierarchy) So he constantly does stuff like installs go to my pc, and leaves his system up and logged in.

        unfortunately I don't live in your well funded and taken seriously IT world.

        • by iron-kurton ( 891451 ) on Thursday August 06, 2009 @06:08PM (#28979619)
          Just a quick question: how hard would it be to give your most malicious user an account named Administrator that was actually not an administrator? <bg>
        • by PsychoSlashDot ( 207849 ) on Thursday August 06, 2009 @08:36PM (#28981103)

          All great points, here are mine.

          1.) We are an architecture office which runs AutoCAD problem is this requires Power User group membership in order to run. (also on windows even without admin privs malicious software can infect.

          No, AutoCAD doesn't require Power User membership. What it requires is someone to spend a few minutes to adjust the system to allow it (and pretty much anything else) to run with User perms only. Do a Google search for Filemon and Regmon formerly from SysInternals and now Microsoft free software. Run them (using RunAs since these DO require admin rights) while your users have normal perms. Set them to only show you what ACAD.EXE does. When it craps out (and it will), search the logs for Access Denied. Manually add perms for Users Full Control to the folders and registry keys that it requires. This will take several passes as the program will run better and better each time. Write down what you have to permit, so next time you install on a new machine you'll know what you need.

          Almost none of my hundreds of supported desktops allow users to have admin rights. The ones I'm not PERMITTED to spend the labour tend to get owned periodically. The non-admin systems don't. Really. Since Win2k's release I have yet to have even one system actually get infected. Light damage, yes. Infected, no.

          What... you think admins running Citrix or Terminal Servers just throw their hands up in the air and accept some lazy-ass vendor's word that their software NEEDS admin rights?

      • Re: (Score:3, Insightful)

        by rsborg ( 111459 )

        This is all easy to do. Why aren't you doing it? For a small office, it wouldn't even be expensive.

        Especially in a small business, your users will rebel if they can't install (or use) their software... which is quite reasonable given most people are still running Windows XP, and most XP software is not capable of being installed or sometimes even used without admin access... this is especially troublesome if that user happens to be the CEO/Owner.

        You hardly ever have time/resources to "do it properly" in

        • by mcrbids ( 148650 ) on Thursday August 06, 2009 @06:52PM (#28980069) Journal

          You hardly ever have time/resources to "do it properly" in a small business, unless what you're "doing right" is a core competency of the business. The trick is to convince the guy who signs the checks that it is business/mission critical (often non-trivial).

          Sure you do! It's called OSX. Now, before you flame me into submission, understand that I'm writing this on my Fedora Core Linux laptop. I'm a command-line junkie extraordinaire, and don't feel comfortable until I have an xterm or three up on one or two virtual desktops while running dual-head.

          But there's a very real, very useful, and very definite benefit to running on OSX - there really is not just nearly as much of a problem with viruses, worms, trojans, and other crapware. Really really for real and yes, it's for real.


          You can argue about marketshare or Unix core or whatever, but it's true - Macs *are* more reliable and *do* have much less of a problem with viruses and such. Who cares why? And if you really must run something windows like, you can get Parallels/VMWare or boot camp. (I recommend the former unless you are a gamer) Even better, if you go the VM route, you can easily save your Windows VM image to an external disk every week or so, and if/when it gets infected, just recover from a backup and be up and running again in minutes instead of days!

          I didn't appreciate OSX until I had to port our software over to it. It was painful at first, but in the process, I fell hard-core in love with OSX. Except for the dated Unix command line, it's everything that Fedora Core ever dreamed of.

          • Re: (Score:3, Insightful)

            You can argue about marketshare or Unix core or whatever, but it's true - Macs *are* more reliable and *do* have much less of a problem with viruses and such. Who cares why?

            You will care about why when the market share numbers change. If MACS were 90% of the market, they'd be the ones with the botnets running on them, and the Windows machines would look just like Macs do to you. And it doesn't need to get to 90% for it to be that way. As the Mac marketshare continues to climb - and it will - you'll find that botmakers will target the Mac platform. They'll find holes. And they'll start to get infected. It is a function not of the OS, but a function of WHO is running them.

      • by peragrin ( 659227 ) on Thursday August 06, 2009 @06:00PM (#28979521)

        for a small office running windows the end users HAVE to run as admin, as Most windows apps require it. My HP printer drivers, and a couple of other apps require my to be fully logged in as an admin or they don't work basically preventing me from doing most of my work.

        I know this as I tried it as I don't believe I should run as admin. Since Windows and MSFT doesn't force developers to code to security standards, including their own. Running as a non admin in a real world environment is impossible. Oh and just to really make you scratch One of those mission critical apps crashes on install because it loads the win16 subsystem for running.

        It gets updated 3-4 times a year but it still requires win16 components. MSFT has enabled that in 2009 that win16 parts are required still. If MSFT would let go of old and outdated parts like the rest of the OS world shit like that wouldn't happen.

        • Re: (Score:3, Insightful)

          by superskippy ( 772852 )

          I hate to break the Slashdot rules-of-posting, but I've got some sympathy for Microsoft here. A lot of the things Vista tried to do was to sweep away some of the old crud and make developers code more securely- that was what the whole Blah wants to do something- confirm or deny bit was about.

          Everyone's reaction? Waaaaahhhh, my computer is far more annoying. Where are my XP disks?

          MS are damned if they do sweep away old insecure crud (because old stuff stops working) and damned if the don't sweep old crud awa

      • by QuantumRiff ( 120817 ) on Thursday August 06, 2009 @06:10PM (#28979647)
        No! You do not put all your effort at one entry point.. I have seen a company that was totally secure from the old "code red" virus because all the firewalls were updated, and public facing servers were patched. The network guys blocked all the appropriate ports at the firewalls. Then, a Salesman came into the office from out at a client site, and hopped on the network to check his email, and his laptop took out everyone.

        You need layers of defense. preferably from different vendors or makers.

        And really, this is Slashdot, why are you recommending Fortigate or ASA? you should be talking up Snort, or its commercial appliance version, Sourcefire.
    • Re: (Score:3, Interesting)

      by whoever57 ( 658626 )

      In addition I check the network once a week for mail or ftp sockets ( evidence there is a bot net at work). So far this has been the easiest way to stay on top.

      I would also block outgoing port 25 and then ask the users what smtp servers they use and whitelist those.

      Getting the users to run as a non-privileged user will make clean-up much easier. Set their normal login to be a low-privilege user (and add network configuration so they can configure wireless networks), then give them their own administrat

      • Re: (Score:2, Funny)

        by Anonymous Coward

        and show them how to login as their normal username and use "run-as".

        Awwww, how cute! He's trying to teach a user something!

        Let's watch...

      • by mlts ( 1038732 ) *

        Actually, you can just block outgoing port 25 and leave it at that. Most E-mail providers use 587 for E-mail submission, and 465 for SSL based E-mail submission.

        The difference is that 25 is intended to talk from a server to another server. 587 is for a MUA like Outlook, Thunderbird, or mutt to send mail to their "local" mail server, and that server controls authentication, then sends it to other servers via port 25. By separating this functionality, admins can block port port 25 completely excep

    • Re: (Score:3, Insightful)

      by gad_zuki! ( 70830 )

      Youre doing it wrong. Set your users to be users, not administrators. Give them permissions to exactly what they need and whatever special permission the applications they run need. Sure, it takes time at first, but once you figure it out then you're good for the rest.

      Or you can take the lazy man's approach and set them as power users, which is almost like an administrator, but selectively remove modify/write permission from c:\windows, c:\program files, and other critical areas. Less secure but a bazill

    • by mlts ( 1038732 ) *

      If the machines are being used as generic hosts without any data saved locally, I'd consider the use of a program like DeepFreeze. This way, even if a user has admin authority on a box, should it get infected, a reboot will scrape all that junk off and roll back to the original frozen configuration. Even better is if the user has no admin authority, because this prevents malware that infects the user's profile from touching LocalSystem level processes.

      I have used utilities that preserve the system state i

  • Close all programs

    c:\>netstat -b
    • Re: (Score:3, Funny)

      by dotgain ( 630123 )

      ... and now imagine I chose 'Plain text'

      c:\>netstat -b
      Your computer is fine.


  • by (H)elix1 ( 231155 ) * <> on Thursday August 06, 2009 @05:08PM (#28978877) Homepage Journal

    Fire up a command prompt and type

    netstat -a | find "LISTENING"

    to find out what ports your system is listening to. Running the netstat command will give you all the traffic. Should give you a good idea as to what is happening. (Helps to close all of your 'normal' apps)

  • by Ilgaz ( 86384 ) on Thursday August 06, 2009 @05:10PM (#28978903) Homepage

    If I had that kind of suspicion and if it was router itself I was suspicious about, I would simply get the latest stable firmware for that particular model (be careful) and simply reinstall it over the router itself. It would be something like "format and install windows" I wouldn't really backup any settings on that case. Just make sure you know ISP login and pwd. Make sure they work, they haven't been changed at any point or you will end up speaking with Bangalore at 4 AM :)

    A simple,fast port scanner exists at [] (shields up!) which really works, ignore Mr. Gibson's weird named inventions like "nano scan" etc. What I know is, it works. Oh also ignore its port 139 or "you aren't stealth" paranoia. 139 is client port and stealth would be good but you won't really die if you have nothing served.

    For clients, don't re invent the wheel. NMAP is there, free and can run under win32 if you need. [] , some instructions exist for detecting current security threats but I didn't really check since it is all OS X here, we have different issues than win32.

  • No (Score:5, Funny)

    by WindBourne ( 631190 ) on Thursday August 06, 2009 @05:11PM (#28978919) Journal
    What it really means is that your dad is a part of an international crime ring and he really is a cracker, without your knowledge. He just felt that you did not have a clue so allowed you to play with his computer.
  • Boot into safe mode, then use a tool such as Autoruns by Sysinternals to see what's starting when Windows loads.

    On an infected system you will see a number of drivers and shell extensions that are not a part of a standard Windows installation. Some of them may be things that were installed by the user, but most of them are malicious software.

    Of course, getting rid of that stuff is an entirely different question.

  • by Anonymous Coward

    The rubotted tool does a pretty decent job of detecting most botted computers. Have your dad download it here: []

    You could also look for his system on the dronebl: []

    Good luck!

    • Re: (Score:3, Informative)

      by HikingStick ( 878216 )
      I've had success using Trend Micro's RUBotted. It monitors for some typical bot behaviors, like making phone-home connections. It was handy around the office when I was trying to track down a bot that wasn't caught by our AV/Firewall product. Once the machines were identified by RUBotted, I was able to remediate them (one I had to nuke, but was able to recover one of the machines).
  • by papasui ( 567265 ) on Thursday August 06, 2009 @05:32PM (#28979195) Homepage
    It makes remarks about wanting to try other operating software. It's unusually concerned about antivirus protection. Plug and Play only works with force-feedback devices. It makes unusually long "hand-shakes" with the email server. It accuses you of installing spyware. It asks you to run your network scans in promiscuous mode. It tells you that it's mainframe never liked you.
  • While my father was cleaning his gun, he loaded it and emptied the clip into his foot. He then reloaded and pumped another four slugs into the same foot. So I was wondering, does any one know where I can get a good deal on Band-Aids? Thanks.
  • Default Settings (Score:2, Insightful)

    by krygny ( 473134 )

    For some reason, he reset the config on the Linksys, and connected it up without wireless security, and also with the default admin password for some time.

    He probably just stuck a pencil in the reset button. Maybe because he was having connection problems for some other reason and that "fixed" it and he was happy. Ignorance is bliss ... for a while.

  • One word:


    Detecting and removing botnet software is its purpose in life. []

  • by ashraya ( 632661 ) on Thursday August 06, 2009 @05:51PM (#28979419)
    A good many replies here - so I will answer a few questions that have been asked.

    1. For this time, I assumed the systems were owned, and they have now been rebuild (Windows Reinstalled).
    2. The Linksys is re-secured - but I hadnt thought of that being owned - so I have to now do a firmware upgrade on that - Thanks for the suggestion.
    3. Other suggestions are to confirm botnet or sniff traffic - I am in the UK, and I can only do so much remotely.
    4. One of the quesions was how I managed to remote into the windows hosts - No, I managed to remote into the Linksys, not the windows hosts.
    5. The bizzarre situation in the Windows host before it was rebuilt was that if we did (I told the commands over the phone for my dad to execute) ping or traceroute to a destination like, it would work. It would resolve the right IP. However, with any of the browsers, as soon as access to a site was attempted - We would get a message "Connection Reset" or the browsers equivalent. (Firefox, Chrome and IE tried). Has anyone seen that one before?
    6. Another question asked was if the Windows in question was legit - Yes, I bought him a OEM XP the last time I was there and installed it.

    • Re: (Score:3, Insightful)

      by Deliveranc3 ( 629997 )
      A Question... "without wireless security, and also with the default admin password for some time. "

      Your implication seems to be that someone wandered by your fathers house, saw an open wireless network and decided to insert packets to own his machine.


      This seems like a pretty unlikely method of building a botnet compared to spam, website security holes, application fail (office, adobe, gif).

      It also seems to support the whole "sharing is bad" mentality that the RIAA and ISPs (and their net neutra
  • by jafiwam ( 310805 ) on Thursday August 06, 2009 @06:06PM (#28979589) Homepage Journal
    Slashdot is doing tech-support for India now?

    Some chick named Alanis is calling you subby.
  • OS Check! (Score:5, Funny)

    by dandart ( 1274360 ) on Thursday August 06, 2009 @06:07PM (#28979599)
    Q: How do I tell if my computer is part of a botnet?
    A: If it's got Windows on it, it is.
    • Re: (Score:3, Informative)

      by ArtemaOne ( 1300025 )
      Its funny though, I've run Windows for a very very long time, and haven't used antivirus for the past decade. I run checks and my system doesn't pass any weird traffic, there are not unexplainable processes or services. I guess I just don't do stupid things to get viruses.
      • Re: (Score:3, Insightful)

        by harl ( 84412 )

        Computer viruses and trojans are social illnesses. Risk of social illness infection is greatly mitigated through behavior.

  • by mrsbrisby ( 60242 )

    Is it running windows?

  • by sgt scrub ( 869860 ) < minus punct> on Thursday August 06, 2009 @06:10PM (#28979643)

    If you are seeing netbios over tcp (port 445) traffic and he is not uploading/downloading files via the "My Network Places" interface he is most likely infected with a trojan.

    If your seeing random high port to random high port traffic (ports 1024 - 65535 connecting to another ports 1024-65535) and he isn't doing P2P then he most likely is infected and the infection is trying to set up the machine as part of a bot net and trying to infect others.

    If you are seeing UDP traffic on a consistent port on his machine to random high ports (1024-65535) on the outside, his machine is an active server in a bot net.

  • You've rebuilt the windows machines? So, now you can not at all be sure if they were part of a botnet or not.
    Chances are they were, and you've done the right thing by rebuilding them.

    I think the details about the router with it's default password an no wireless security is a red herring - I've not heard of a botnet that tries to get in to your network by guessing standard admin passwords for common wireless routers. More likely it was a drive-by download from a dodgy web page, or a trojan in some downloaded software that put the malware on the machines.

  • Securing Linux Box? (Score:4, Interesting)

    by Lotana ( 842533 ) on Thursday August 06, 2009 @06:43PM (#28979979)

    While we are on a topic of security:

    Several months ago I started using Debian as my primary OS at home. I am very happy with it, but don't know much about how to keep it secure or how to tell if I had been compromised. Of course very basics are clear: I do not use root except in those instances of updates, etc. The consensus on this site is that if you run Linux then you are invincible, but I respectfully disagree. The system is only as secure as the competence of the user.

    To cut the long story short:

    - What do you normally do to make sure that your Linux system is clean? Is running apt-get upgrade regularly enough or is there more to it?

    - What articles or books would you recommend to a newbie in this area? I am fully willing to RTFM as such, but please at least give me at least some direction on what to search for.

    - Any other general tips, advice or wisdom would you be willing to share?

    Thank you

    • Re: (Score:3, Informative)

      by Gogo0 ( 877020 )

      -i heard its good to remove SUID from any binaries that have it set. check google for this, its some long command that involves xargs.

      -check your /var/log/auth.log from time to time and make sure there arent a bunch of failed login attempts.

      -if you see a lot of activity in auth.log and other logfiles pointing to repeated attempts at breaking into your system, identify the method theyre trying to get in through (usually ssh or ftp) and change the port. i usually use 2222 for ssh and 2121 for ftp, that stoppe

  • The takeaway... (Score:5, Interesting)

    by Chysn ( 898420 ) on Thursday August 06, 2009 @09:08PM (#28981367)
    I've read this entire thread and learned that it's impossible to tell if your computer is part of a botnet.
  • The Shark (Score:4, Informative)

    by bizitch ( 546406 ) on Thursday August 06, 2009 @10:09PM (#28981763) Homepage

    Download and install Wireshark from []

    Fire it up and watch everything on the NIC

The last thing one knows in constructing a work is what to put first. -- Blaise Pascal