Yeah, definitely a scan. Snort detects it as an NMAP XMAS scan, but in reality, it could be any packet crafting tool (nemisis, hping2 or nmap).
Heres a sample packet that's hit my IDS with a SRC PORT of 5635:
-----------------
#(1 - 8041) [2001-07-10 18:50:38] NMAP XMAS scan
IPv4: 212.111.188.176 -> 194.130.109.65
hlen=5 TOS=0 dlen=106 ID=64773 flags=0 offset=0 TTL=111 chksum=19876
TCP: port=5635 -> dport: 0 flags=**U*P**F seq=1359020032
ack=1292042247 off=0 res=2 win=43093 urp=9716 chksum=7155
Payload: length = 66
000 : 40 CC C6 34 62 66 E0 DF FF 1D 86 BE 4E F6 BF 60 @..4bf......N..`
010 : 70 95 33 11 C9 1A 0F 20 AB 63 27 36 F1 C9 D4 D3 p.3.... .c'6....
020 : B9 00 DC 4F 44 E1 83 25 AB 47 7D 20 CB DB EE BC ...OD..%.G} ....
030 : 42 9C 21 BE 5C 95 1B A2 00 06 00 03 00 08 00 06 B.!.\...........
040 : 01 00 ..
-----------------
Rgds,
Scott
Curt Purdy wrote:
>
> IMO, this looks like an hping2 scan. See
> http://project.honeynet.org/scans/arch/scan1.txt for a sample honeynet scan
> that is just the opposite (dest 0 - src high port). But as they explain,
> the default hping2 is actually (scr 0 - dest high port) as in your case.
>
> Curt Purdy
> Information Systems Engineer
> DP Solutions
>
> -----Original Message-----
> From: rltat_private [mailto:rltat_private]
> Sent: Tuesday, July 10, 2001 10:11 AM
> To: incidentsat_private
> Subject: TCP Src 5635: what is it?
>
> Just a little help needed here. I've been seeing a lot of traffic with
> a source port of 5635 and a destination port of 0. Searching on google
> yields no significant results. There were two forums that asked the
> same question and haven't yet gotten an answer. I asked the posters for
> more information and if there problems had been resolved but I haven't
> gotten a response yet. So, any help and or insight would be much
> appreciated.
>
> Here's an excerpt from my logs:
>
> Time,Source Addr,Source Port,Dest Addr,Dest Port,TCP/UDP,TCP Flags
> ,,,,,,
> 6/28/01 15:41,208.33.170.61
> (cvxp061.intrstar.net),5635,Host.In.Our.DMZ,0,TCP,
> 6/28/01 15:41,208.33.170.61
> (cvxp061.intrstar.net),5635,Host.In.Our.DMZ,0,TCP,fin rst psh
> 6/28/01 16:55,63.254.34.74 (A010-
> 0074.FRDK.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn psh
> 6/28/01 17:50,208.33.170.154
> (cvxp154.intrstar.net),5635,Host.In.Our.DMZ,0,TCP,rst
> 6/29/01 0:04,63.252.82.9 (A010-
> 0009.FTVL.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst psh ack
> urg
> 6/29/01 0:04,63.252.82.9 (A010-
> 0009.FTVL.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst
> 6/29/01 0:04,63.252.82.9 (A010-
> 0009.FTVL.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,rst urg
> 6/29/01 7:26,63.255.89.15 (A010-
> 0015.HIPT.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:26,63.255.89.15 (A010-
> 0015.HIPT.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:26,63.255.89.15 (A010-
> 0015.HIPT.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:26,63.255.89.15 (A010-
> 0015.HIPT.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:26,63.255.89.15 (A010-
> 0015.HIPT.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:27,63.255.89.15 (A010-
> 0015.HIPT.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:28,63.255.89.15 (A010-
> 0015.HIPT.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,psh urg
> 6/29/01 7:34,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:34,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:34,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:34,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
> 6/29/01 7:35,209.156.206.217 (A020-
> 0979.GNBO.splitrock.net),5635,Host.In.Our.DMZ,0,TCP,fin syn rst urg
>
> The TCP flags are varied. I know it's not indicated here but I didn't
> want to send the entire list of attempts.
>
> There server that these IP's are destined for happens to be a HTTPS
> server. And these IP's have also established full connections with the
> server. So I'm not sure if this is an attack or some wacky software mis-
> configuration.
>
> Again, any help and or insight would be appreciated.
>
> Thanks in advance.
>
> -Rick
>
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--
Scott Nursten - Systems Administrator
Streets Online Ltd.
Direct: +44 (0) 1293 744 122
Business: +44 (0) 1293 402 040
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Email: scottnat_private
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