Advanced IIS unicode scanning?

From: Gossi The Dog (gossiat_private)
Date: Fri Jul 06 2001 - 19:22:37 PDT

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    Spotted this is the snort logs just now..
    
    [**] spp_http_decode: IIS Unicode attack detected [**]
    07/06-20:28:42.154535 145.253.21.36:63451 -> 212.158.123.230:80
    TCP TTL:49 TOS:0x0 ID:59 IpLen:20 DgmLen:279
    ***AP*** Seq: 0x3E80FDA  Ack: 0x6FAB9FDD  Win: 0xFFFF  TcpLen: 32
    TCP Options (3) => NOP NOP TS: 331337 5745821
    
    Few hundred lines of it.  The Ack's are all the same, source ports varies
    slightly but not in any sort of order (as in, doesn't look to have come
    from a standard Windows box).
    
    Notice the last TCP options line - 331337.
    
    [gossi@owned gossi]$ nslookup 145.253.21.36
    Server:  inh1dns02.ims.bt.net
    Address:  193.113.185.228
    
    Name:    cache3-1-stg.arcor-ip.net
    Address:  145.253.21.36
    
    
    Possibly just the fingerprint of somebody using a proxy to scan for
    the Unicode bug?
    
    
    
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