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Thread: What are DoS or DDos?

  1. #1

    What are DoS or DDos?

    Can anybody tell me what are DoS and DDoS attacks and what are its variants? How are they originated. I would be really thankfull
    There is no Gravity. Its only because earth SUCKS!!!

  2. #2
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    DOS - Denial of Service
    Thats when one computer is used to overwhelm another till it has crashed.

    DDOS - Distributed Denial of Service
    Thats when multiple computers are used to target one computer.

    Basically the DOS attack is an attempt to overload a computer with information that it cannot accept anymore legit requests. Alot of the DOS attacks you see are aimed @ web servers and what not. I've seen DOS attacks from 45KB a sec to over 900Mb a sec @ one computer. As you might imagine having all that information attacking one computer can overwhelm it very quickly.

    DOS attacks can also be used to overwhelm networks. If you have a 100Mbps network it won't take much over 95Mbps to make your network sluggishly slow. A few more Mbps and your network is down.
    =

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    DoS definition: Denial of Service. An attack that is not virus-based, but a action preformed by crackers to prevent or deny legitimate users access to a computer. This can include a flood of information that overloads what a server can handle, and thus causing it to lag or crash; to even forcing an FTP account to lock down because someone deliberatlly gave it the wrong login password so many times that the system shut down that users account.

    DoS example:
    Smurf DoS Attack - http://securityresponse.symantec.com...os.attack.html


    DDoS definition: Distributed Denial of Service. Similar to a DoS, but on a MUCH larger scale. Distributed Denial of Service attacks are done from multiple attack servers (or even home computers that are infected with a trojan/virus), which are remotely controllable by a cracker. All of those computers combined together launch a DoS upon a target. Think of it like Vultron when all of the robots came together to form a more powerful robot. Same concept, but a stronger and more deadly DoS.

    DoS example:
    Trojan Zombies that remain in someone's computer silently, until the remote user activates this. this attack was used in bringing down yahoo.com when thousands of zombied computers pinged yahoo.com over and over until the server couldn't handle the load and crashed out.
    \"It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.\"
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  4. #4
    this can include a flood of information that overloads what a server can handle, and thus causing it to lag or crash;
    How can we send a large amount of data to particular network untill or unless are autorized to do so.

  5. #5
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    How can we send a large amount of data to particular network untill or unless are autorized to do so.
    A few ways:

    1. Access a webpage over and over and over and over and over and over again.
    2. Use the ping command to send constant ICMP-based data over and over and over again
    3. Send "garbage" data packages (to put it in non techincal terms). Even if it is garbage, the computer target still has to take the time to register what you are sending it, verify it as junk, and then tell you that it was rejected. Do that over and over again. There are a few ways to send junk data packages, but most involve crafting your own UDP/TCP/ICMP/IP packets.
    \"It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.\"
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  6. #6
    T3h Ch3F
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    Originally posted here by guardian alpha
    A few ways:

    1. Access a webpage over and over and over and over and over and over again.
    2. Use the ping command to send constant ICMP-based data over and over and over again
    3. Send "garbage" data packages (to put it in non techincal terms). Even if it is garbage, the computer target still has to take the time to register what you are sending it, verify it as junk, and then tell you that it was rejected. Do that over and over again. There are a few ways to send junk data packages, but most involve crafting your own UDP/TCP/ICMP/IP packets.

    Good info, just a subnote to this.

    Most servers/routers are equiped with filters to deny these type of attacks, and will usually dispense with repetitive packets. On a good day it will result in no down time.

    P:
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  7. #7
    Denial of service is simply that. Your denying access to web-services and its not always associated with flooding, ya morons.

  8. #8
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    Denial of service is simply that. Your denying access to web-services.
    I take it you didn't read the very first line of my post here? No reason to resort to calling people 'morons' either.
    \"It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.\"
    - Charles Darwin

  9. #9
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    Most servers/routers are equiped with filters to deny these type of attacks, and will usually dispense with repetitive packets. On a good day it will result in no down time.

    this is where DDoS comes into play, sure the router blocks the packets after a bit, but if you execute successfully you can drop a router in seconds. not to mention the fact that many people doing these attacks first crack the router and then attacka node within the network itself or an even more important router. AND once you crack a router or node on a network the other routers know that its an internal IP and allow the traffic. so it is very possible and somewhat easy to launch a DDoS attack, especially on a smaller scale like a school or small business.
    Everyone is going to die, I am just as good of a reason as any.

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  10. #10
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    sure the router blocks the packets after a bit, but if you execute successfully you can drop a router in seconds
    Wouldn't in theory there be more stress on a router trying to filter packets that are malformed or fragmented, than if it wasn't? And thus, do you think that a stateful router blocking advanced packet configurations is going to drop(crash/lag) faster than it the router wasn't worried about it?
    \"It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.\"
    - Charles Darwin

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