Re: Unusual volume: UDP:137 probes

From: Scott McGee (scottmcgeeat_private)
Date: Mon Sep 30 2002 - 11:27:02 PDT

  • Next message: Bamm (Robert) Visscher: "RE: Unusual volume: UDP:137 probes"

    Here are some example tcpdumps of the netbios probes:
    
    tcpdump -xX -v -i eth1 udp port 137
    
    11:10:54.373723 200-158-48-226.dsl.telesp.net.br.1025 >
    ca-crlsca-cuda2-c6a.crlsca.adelphia.net.netbios-ns:  [udp sum ok]
    >>> NBT UDP PACKET(137): QUERY; REQUEST; BROADCAST
    TrnID=0x100
    OpCode=0
    NmFlags=0x1
    Rcode=0
    QueryCount=1
    AnswerCount=0
    AuthorityCount=0
    AddressRecCount=0
    QuestionRecords:
    Name=*               NameType=0x00 (Workstation)
    QuestionType=0x21
    QuestionClass=0x1
    
     (ttl 102, id 22089, len 78)
    0x0000   4500 004e 5649 0000 6611 c8a8 c89e 30e2
    E..NVI..f.....0.
    0x0010   4446 f7e6 0401 0089 003a 85f9 0100 0010
    DF.......:......
    0x0020   0001 0000 0000 0000 2043 4b41 4141 4141
    .........CKAAAAA
    0x0030   4141 4141 4141 4141 4141 4141 4141 4141
    AAAAAAAAAAAAAAAA
    0x0040   4141 4141 4141 4141 4100 0021 0001             AAAAAAAAA..!..
    
    11:12:25.241600 209.136.250.227.1030 >
    ca-crlsca-cuda2-c6a.crlsca.adelphia.net.netbios-ns:  [udp sum ok]
    >>> NBT UDP PACKET(137): QUERY; REQUEST; BROADCAST
    TrnID=0x100
    OpCode=0
    NmFlags=0x1
    Rcode=0
    QueryCount=1
    AnswerCount=0
    AuthorityCount=0
    AddressRecCount=0
    QuestionRecords:
    Name=*               NameType=0x00 (Workstation)
    QuestionType=0x21
    QuestionClass=0x1
    
     (ttl 46, id 7690, len 78)
    0x0000   4500 004e 1e0a 0000 2e11 65fc d188 fae3
    E..N......e.....
    0x0010   4446 f7e6 0406 0089 003a b308 0100 0010
    DF.......:......
    0x0020   0001 0000 0000 0000 2043 4b41 4141 4141
    .........CKAAAAA
    0x0030   4141 4141 4141 4141 4141 4141 4141 4141
    AAAAAAAAAAAAAAAA
    0x0040   4141 4141 4141 4141 4100 0021 0001             AAAAAAAAA..!..
    
    
    | >
    | > Packet contents seem to be "normal".
    |
    | Yep. Look normal here too.
    |
    
    
    Scott
    
    
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